Leigh M. Smith

LANDR

Leigh — Sat, 17 Oct 2015 17:23:32 +0000

I've recently moved onto some new music information retrieval projects. I moved on from Humtap (wishing them ongoing success!) to MuseAmi in June but unfortunately they made a big strategic pivot in August and downsized the company by a third, myself included. Sad of course, but ultimately start-ups sometimes need to make tough decisions.

A fun trip to attend ISEA 2015 in Vancouver and hang out with my buddy Jordan Yerman, has lead to an ongoing electronic art project, the Street Cat Photo Booth. This is a project we're working on leveraging networked web cameras, machine learning and street kitties!

I'm now also doing some fun work with LANDR as a Senior Research Scientist, doing machine learning based automated music production mastering. This is a great bunch of folks, doing some very cool work, hope to be able to provide more details in the future.

Humtap launched

Leigh — Wed, 17 Dec 2014 01:19:32 +0000

The project I've been working on for the last eight months has now released our first public release. Humtap is a mobile app for collaborative music making. Users collaborate by each recording hums and taps into their mobile phones. These audio recordings are transcribed and become musical avatars. A user can then create a piece of music (currently of the electronica genre) by combining their hum or tap with another user's tap or hum, or with their own tap or hum. Finally, users can also create a new piece of music by combining two other user's hum and tap. The app combines the transcriptions in a musical way and selects the electronic instrumentation. The goal is to enable non-musicians to be engaged in the musical creative process (if you can hum or tap, you can make music).

You sign into Humtap using your Facebook id, mainly so we can get a picture of you to represent your musical creation, without having to police what people upload. Initially, it's only for Apple iOS devices, but stay tuned... Visit www.humtap.com/app to get the app (it's free).

See See Rider - The Pleasures Programmes Live at the Theatre for the New City

Leigh — Sat, 07 Jun 2014 19:23:29 +0000

Reprising the show we did a couple of years back, a "leaner" Pleasure Programmes, consisting of Elizabeth Soychak and myself, play a couple of tunes at the Theatre for the New City as part of the Lower East Side Festival on May 23rd. We did a couple of tunes in a packed programme of different performers, this is our version of See See Rider by Ma Rainey, made famous by Ella Fitzgerald.

the_pleasure_programmes_see_see_rider.mp3

Corcovado - The Pleasure Programmes Live at the Theatre For the New City

Leigh — Sat, 07 Jun 2014 19:20:16 +0000

the_pleasure_programmes_corcovado.mp3

Contracting

Leigh — Tue, 22 Apr 2014 15:37:26 +0000

Since March, I am now independently contracting to a number of companies doing music and audio DSP and machine learning. This is a great opportunity for me to work with and advise a number of really great companies, particularly small startups, on commercial applications of audio signal processing, machine learning, information retrieval, cloud infrastructure. You can check my biography for more details.

BreakTweaker released using MediaMined Discover

Leigh — Thu, 23 Jan 2014 18:15:21 +0000

iZotope today announced BreakTweaker a drum machine and synth DAW plugin incorporating MediaMined Discover for content based searching of its sample libraries. The video demo does not discuss the feature, but you'll see the "Discover" button on the Sample window at 1:40 in the video.

All of the factory content has been indexed by MediaMined Discover for timbral similarity. This allows finding new drum samples based on examples users are already working with. BreakTweaker doesn't do searching by text tags or names of files, but instead, presents a list of samples that acoustically most closely match the current sample. This allows BreakTweaker users to try drum samples that sound similar but provide variety to the current sound. The aim is to stream line the process to create evolving and varied drum tracks.

Building a Roland 24 pin guitar synth cable

Leigh — Tue, 05 Nov 2013 20:52:24 +0000

DIY Connector with GR synths: View of DIY connector, GR-300 and GR-100 in the background.

The first generation of Roland guitar synthesisers used a totally unique 24 pin connector. This was apparently built specifically for Roland and was never used by any other manufacturer. Consequently, the connectors and cables are hard to find and tend to fetch crazy prices on Ebay. Wayne Joness site goes into the issue in depth. Quite some time ago, I moved to using ubiquitous DB-25 pin connectors to replace the 24 pin connectors on my guitars. This is an approach also done by Wayne. While I was happy to mod the instruments (since they are mostly modified in other ways as well, so keeping them stock is not important), I didn't want to mod the guitar synths, such as a GR-100, GR-300 and BX-13 (Wayne's 24 pin to 13 pin adapter), since it is more work (particularly on the GR-100).

The solution is to create DB-25 to Roland 24 pin cables, matching the pin numbers from the 24 pin to the DB-25 (the same pinout conversion standard is used by Wayne). I had done this in the past by salvaging the male 24 pin connector from the guitar and moving it to the special cable, and I modified an old metal printer cover. However, these covers can also be hard to source. I also needed an extra male 24 pin connector.

Inspired by a posting by rdunna on instructables about his efforts building a 24 pin male connector, I did something similar. Instead of using circuit board for the base to mount the edge connector pins, I opted for an off cut of perspex. This was drilled with a 1/32" drill bit using the trusty Dremel with it's drill press attachment.

Base of DIY connector: After drilling the perspex base, even with a drill press, I was off in my alignment…grrr. This was a combination of using a broken 1/32" drill bit, inaccuracy of the Dremel drill press base and that I didn't centerpunch the marked drill holes accurately enough, nor checked the prospective drill hole position sufficiently. Other photos indicate that this level of inaccuracy didn't turn out to be a problem in practice. The edges of the perspex in this photo are pretty rough, due to cutting the perspex with a hacksaw by hand (no bandsaw available). After this photo, I flattened and straightened the edges with a hand file. Some of the edge connector pins and 1" 2-56 bolt for reference. I ended up using a 1/2" bolt as a centre pin.

I created a scaled version of the original image posted by rdunna so it could act as a 1:1 drill template (see below for downloadable PDF). Print this with no scaling should give you the correct spacing for a drill template. To attach the edge connector pins I used epoxy glue, using a spare piece of perspex spaced 5mm from the base to ensure the pins are all the right depth. Before the glue completely hardened (i.e after a couple of hours of drying), I aligned the pins into the female connector to ensure the pins were exactly right.

Edge connector pins glued: Here the edge connector pins have been glued with 24 hour epoxy glue, together with a 1/2" 2-56 bolt and are drying with the pins gently positioned into a female Roland 24 pin connector. I happened to have one spare, but you could use a synth's connector for the alignment. This will compensate for the inaccuracy of the drilling. For the first couple of hours drying, I had set the connector 5mm distance from another piece of perspex, held apart by bolts to ensure the connector pins all extend to the correct depth. The 1/2" bolt turned out to descend the correct depth due to the thickness of the perspex, otherwise I would have cut it down with the Dremel.

I used a 2-56 1/2" screw as the alignment pin which needs to protrude 10mm from the perspex base.

With the connector itself built, the cover was the next task. After considering a number of approaches, since I had some rectangular aluminium extruded tubing available, that became a slip on cover.

Aluminium rectangular tubing used for cover

Using some 1/2" L shaped channel, I cut and drilled the strip to allow bending (very gently as aluminium will break). All the holes were drilled with a drill press.

Aluminium tubing cut, angle cut, drilled and bent: The aluminium tubing outer covers have been cut and hand filed, the 1/2" aluminium angle has been cut, drilled and bent. Shown with the stripped wires of a Belkin cable and an original Roland 24 pin connector.

Two side screws hold the interior and exterior portions and allow disassembly. Fitting a strain relief and a couple of cable ties makes the connector rock & roll robust. I wouldn't assume it's of the same robustness as the originals in terms of continuously unplugging and plugging in, but for situations where it mostly remains connected, it works fine for me, as shown installed into the (pretty grubby) GR-100.

Connector operational: The connector correctly mounted and working in a very dirty GR-100!

I built two, the first with an original male 24 pin connector, the second with a home made connector. Overall, not too difficult to produce something that works, although building a female version would be quite a bit more work. Perhaps a 3D printer combined with adapting some other multi pin metal socket would be suitable. If anyone is interested in pursuing this, contact me as I have a near complete 3D model of the Roland 24 pin female connector.

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scaled_roland24_pinout2.pdf	6.82 KB

Setting up an Ibanez IMG-2010 Guitar Synth controller

Leigh — Wed, 30 Oct 2013 00:31:45 +0000

I have the joy of owning an Ibanez IMG-2010 Guitar Synth, which can be had quite cheap on Ebay, yet are excellent quality Steinberger style guitars, and originally sold for quite a princely sum. Wayne Joness' very informative GR-300 site extolls the qualities of this beast in great detail. I'm yet to do the conversion to a DB-25 pin connector and fit the G-202 hex fuzz circuit, but it's planned.

One slightly tricky issue with them is that being a headless neck, the truss-rod tightening bolt is located at the base of the neck between the neck pickup, under the fingerboard lip. This is an Allen key which needs to be shorter than normal in order to get in around the tight corner. Ibanez used to ship a special short length Allen key, but my S/H instrument never came with it. After searching around for exactly how much to cut down an Allen key and what dimensions to use, I had to resort to some trial and error, cutting down the key progressively (be careful as removing too much will not allow the key to sit in the bolt socket). Previous Ebay postings had indicated it was a 5mm width Allen key (likely easily obtainable in the U.S. via your last Ikea furniture package). I ended up cutting it down to 15mm, although the image shows it 0.89mm more than that (I assume it was originally specified as 15mm), using a Dremel tool with the metal cut off wheel.

When doing this, follow all the usual safety precautions - cutting hard steel down will kick up many sparks, so wear proper eye protection and be careful that the key will become hot, and lightly file over the edges of the cut to remove the sharpness and ensure the key doesn't catch on the edge of the bolt.

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IMG-2010 truss-rod tool	48.18 KB
Dremel metal cutoff wheels	60.09 KB

Downgrading Apple Airport Express 802.11g (A1084) firmware

Leigh — Sun, 13 Oct 2013 01:16:37 +0000

I've had an Apple Airport Express 1st Generation, 802.11g model A1084 since new, c. 2004. This has long been superseded by newer versions, and for sometime it was just doing duty for me as a USB print server, not as a router. However, it seems that there is a bug introduced around v6.2 of the firmware that would cause it to go offline when configured to "join wireless network". Restarting the AE would allow it to run, but it would soon drop off the net. It became particularly troubling as it would become unresponsive almost as soon as it was configured, barely even allowing a single print job to be sent. It's not clear what the cause is or where exactly the bug may lie.

The bug always appears for me, but there were not a lot of reports about this issue, with one exception that finally solved it for me. I really noticed the problem with v6.3, but downgrading to v6.2 also continued to demonstrate the problem. However v6.1.1 seems to work.

The problem is exacerbated by Apple abandoning support for the 1st gen AE 802.11g in their Airport Utility after V5.6.1. For example Airport Utility V6.3.1 recognizes the device, but refuses to allow any configuration of it. What's really annoying is that you can run Airport Utility 5.6.1 on MacOS 10.8.5 but you need to break the app out of it's installer package as the installer refuses to install the app on later MacOS versions. Unfortunately, it seems with MacOS 10.9.X (Mavericks) the old 5.6.1 app will no longer run. This is presumably because of code signing, since I tried thinning the PPC version with lipo to no avail. I'm yet to figure out a solution to this, and frankly this only highlights the appalling support of Apple in abandoning it's hardware.

This is a damning indictment of closed source software, particularly with Apple's use of a desktop app to do the device configuration without providing a web interface. I even contemplated what would be involved in getting a minimal Linux port onto the AE, since it runs VxWorks now. This can be demonstrated with the following command in the Terminal after installing nmap (I recommend Fink). XXX.XXX.XXX.XXX is the IP address of the AE.

% sudo nmap -v -O XXX.XXX.XXX.XXX
...
MAC Address: 00:14:51:78:55:5D (Apple Computer)
Device type: general purpose
Running: Wind River VxWorks
OS CPE: cpe:/o:windriver:vxworks
OS details: VxWorks

The only real way to recover the AE after it hangs is by doing a hard reset of the firmware back to factory settings. This is done by holding down the tiny reset button and powering on, continuing to hold the button for 20 seconds or more until the LED starts flashing rapidly. It is possible to downgrade the firmware, if you have the earlier versions of the firmware. These are found in earlier versions of the Airport Utility version XML file. I downloaded the v6.1.1 version using curl:

% curl -o airport_express6.1.1.baseBinary http://apsu.apple.com/data/102/061-3060.20070321.cVxe4/6.1.1.basebinary

But you could also just save the file using a web browser. If you do so, give it an extension of .baseBinary, e.g. airport_express6.1.1.baseBinary. The URL relates to the ProductID 102, which is the AE 1st gen. The MD5 checksum for the v6.1.1 file is 40970abbf6f7c1091161873e5d97142d.

With Airport Utility v5.6.1 broken out from it's installer and renamed Airport Utility_5.6.1.app so as not to clash with the new Airport Utility, each time you start that app, click Cancel to ignore upgrading to the latest AirPort Utility. You can then downgrade the firmware by selecting Base Station->Upload Firmware... and choosing Other... for Upload Version and then navigate to where you saved the airport_express6.1.1.baseBinary or whatever you called it.

You should find after upgrading and rebooting, the AE is reasonably robust again and can still do a serviceable job as a print server. There may be some missing functionality in v6.1.1 in it's RAOP support (i.e. AirTunes), and v6.1.1 only supports WPA personal, not WPA2 personal, so you need to ensure your main router has both protocol support enabled (that caught me). However, this keeps an old piece of hardware running, which saves money and keeps e-waste and unnecessary consumption down.

MediaMined video

Leigh — Fri, 21 Jun 2013 04:30:28 +0000

I'm woefully late in pointing this out, but there is now a video done by Matt Hines and Jay Leboeuf explaining MediaMined.

Probing neural mechanisms of music perception, cognition, and performance using multivariate decoding

Leigh — Fri, 21 Jun 2013 04:13:43 +0000

Authors:

Rebecca S. Schaefer, Shinichi Furuya, Leigh M. Smith, Blair Bohannan Kaneshiro and Petri Toiviainen

Psychomusicology: Music, Mind and Brain, 22(2):168–174, 2012

Abstract:

Recent neuroscience research has shown increasing use of multivariate decoding methods and machine learning. These methods, by uncovering the source and nature of informative variance in large data sets, invert the classical direction of inference that attempts to explain brain activity from mental state variables or stimulus features. However, these techniques are not yet commonly used among music researchers. In this position article, we introduce some key features of machine learning methods and review their use in the field of cognitive and behavioral neuroscience of music. We argue for the great potential of these methods in decoding multiple data types, specifically audio waveforms, electroen- cephalography, functional MRI, and motion capture data. By finding the most informative aspects of stimulus and performance data, hypotheses can be generated pertaining to how the brain processes incoming musical information and generates behavioral output, respectively. Importantly, these methods are also applicable to different neural and physiological data types such as magnetoencephalography, near-infrared spectroscopy, positron emission tomography, and electromyography.

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Automated classification of music genre, sound objects, and speech by machine learning.

Leigh — Fri, 21 Jun 2013 04:10:27 +0000

Authors:

Leigh M. Smith, Stephen T. Pope, Jay Leboeuf and Steve Tjoa

Proceedings of the 12th International Conference on Music Perception and Cognition, page 943, Thessaloniki, Greece, July 2012. ICMPC/ESCOM. (abstract).

Abstract:

A software system, MediaMined, is described for the efficient analysis and classification of auditory signals. This system has been applied to the tasks of musical instrument identification, classifying musical genre, distinguishing between music and speech, and detection of the gender of human speakers. For each of these tasks, the same algorithm is applied, consisting of low-level signal analysis, statistical processing and perceptual modeling for feature extraction, and then supervised learning of sound classes. Given a ground truth dataset of audio examples, textual descriptive classification labels are then produced. Such labels are suitable for use in automating content interpretation (auditioning) and content retrieval, mixing and signal processing. A multidimensional feature vector is calculated from statistical and perceptual processing of low level signal analysis in the spectral and temporal domains. Machine learning techniques such as support vector machines are applied to produce classification labels given a selected taxonomy. The system is evaluated on large annotated ground truth datasets (n > 30000) and demonstrates success rates (F-measures) greater than 70% correct retrieval, depending on the task. Issues arising from labeling and balancing training sets are discussed. The performance of classification of audio using machine learning methods demonstrates the relative contribution of bottom-up signal derived features and data oriented classification processes to human cognition. Such demonstrations then sharpen the question as to the contribution of top-down, expectation based processes in human auditory cognition.

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icmpc2012-lms_extended_abstract.pdf	72.79 KB

Retro bike light

Leigh — Wed, 09 Jan 2013 21:19:34 +0000

I'm a big fan of urban biking, having had the privilege of living in Amsterdam and Paris which are both very bike friendly cities for daily commuting. Returning back to NYC, I got a cast off commuter bike from a neighbour, that after considerable work, I got in working order. Given drivers in NYC are nowhere near as aware of cyclists as European drivers, lights are essential. I fitted the crappy old "Fairway Flyer" with a Dutch magneto (aka "dynamo" although that term is strictly incorrect) generator and 6VAC old school chrome light. In practice, the drag on wheel isn't enough to notice given the entire bike is hardly built for speed.

Fast forward to Hurricane/Storm/Climate Induced Disaster Sandy, where in the process of cleaning out our flooded basement, I acquired an 80's Univega Gran Turismo 10 speed bike with a rusted back wheel and jammed seat post. I cleaned that up and in the process felt it was time to reacquaint myself with the joys of touring bikes (from my college days) and upgrade to something better than the Fairway Flyer. Selling off the Univega, I picked up an old 12 speed 80's Peugeot Monaco (both on craigslist), which is a fun bike to ride and suitably retro.

That lead back to needing lights. A magneto would be a crime on a performance bike, but I'd already got complements on my very retro looking light. The solution was to remove the reflector and incandescent lamp from the old metal light housing and insert a battery powered LED light inside. This involved cutting down the LED light with a Dremel, and removing the front plastic cover since the metal light housing has it's own plastic transparent cover. I drilled out the metal housing to accept a normal-off momentary push button, and wired that to the small circuit board inside the LED lights. That required drilling two holes in the PCB to solder the wires to the traces near where the original rubber button would contact.

The result is a fixed light (that I don't need to remember to remove) that will flash in too many different ways (over-design!) that still looks very much in style with the rest of the bike.

iZotope hiring MediaMined interns!

Leigh — Thu, 06 Sep 2012 16:23:11 +0000

If you are a budding music or audio engineering undergraduate student, iZotope is hiring paid interns. The work mostly consists of auditioning our systems.

iZotope hiring MediaMined developers!

Leigh — Fri, 24 Aug 2012 15:15:34 +0000

The MediaMined team at iZotope is expanding! We're hiring software developers with a background in web application development. If you are a LAMP rockstar and care deeply about music, we'd love to hear from you!

The Pleasure Programmes at the Theatre for the New City

Leigh — Thu, 14 Jun 2012 14:14:32 +0000

(Folks That Live On The Hill, by Jerome Kern)

I've been jamming jazz standards with some good friends, Elizabeth Soychak, Sam Coley and Matt Winch, with our tongue-in-cheek band name "The Pleasure Programmes" (named after a cheesy title from a fake book of "suggested collections" of music). We recently had the opportunity to perform at the Theatre for the New City in the East Village, NYC as part of the Lower East Side arts festival. We ended up being downstairs in a very boomy concrete box, so the audio isn't spectacular (my guitar sounds thin, and the bass is muffled), but it was a performance we were pretty happy with.

Jill did a great job shooting and editing our performances!

(Darn that Dream, by Jimmy Van Heusen and Eddie de Lange)

(Desafinando, by Antonio Carlos Jobim)

(Behave Yourself, by Roger Shore)

iZotope acquires Imagine Research

Leigh — Tue, 13 Mar 2012 17:12:06 +0000

The company I have been working with for about 18 months now, Imagine Research has now been acquired by iZotope Inc. based in Boston. This is a great opportunity for us to continue to develop our MediaMined technology, to broaden it's reach and incorporate it into iZotope's future products. For my local friends, I'll continue to be based in NYC.

Jill's video interview with Peter

Leigh — Wed, 16 Nov 2011 15:22:19 +0000

Jill produced a beautiful interview that we made with my Dad, Peter, first shot after his diagnosis, and Jill rapidly edited it ready for playing at his wake. It was a deeply moving way for Dad to be there for all of the people that loved him.

Mediamined

Leigh — Tue, 15 Nov 2011 14:22:13 +0000

Mediamined is a project I've been working on together with the great folks at Imagine Research for about a year now. With some help from the U.S. National Science Foundation, we're now making public some of our technology.

Mediamined offers the ability to classify sound files into a taxonomy of text labels by analysing the audio signal. We use machine learning techniques to learn the acoustic signatures that correspond to what a bass guitar, male vocals or door slam sounds like, and then classify new sounds according to those signatures. Another capability is to use those signatures to determine acoustic similarity between audio files. This can be used for finding music which is most similar to a query sound file, or to find alternative sound effects, as our CEO Jay explains in a video interview.

Some other write ups have appeared including a nice article on Lockergnome.

My Tribute to Dad

Leigh — Sat, 08 Oct 2011 03:19:52 +0000

This is the tribute I presented with my sister Gaye at my father, Peter John Smith's funeral:

I'd like to talk about Dad's life through some of our personal experiences and recollections of him.

I remember how as a young boy, perhaps 11, I was (as was typical) obsessed with making model tanks & soldiers. As part of my obsession, I had discovered somehow that there was a plastic modelling society in Fremantle. With very little pleading, Dad, with Mum and Gaye, would drive me all the way from Darlington to Fremantle on a Sunday afternoon, every month, to participate in the meetings. They'd let me socialise with older enthusiasts, and take Gaye roller skating. It must have cost them a fortune in petrol, but that was just something Dad and Mum did, just because it was something I wanted to do, and they'd accommodate me, with no complaints. That sense of cheerful sacrifice underpinned Dad's service to the many community groups he was a part of.

As a younger boy, perhaps 5 or 6, he would always be making something for me, be it a crossbow (thoughtfully he ensured it didn't really work), or a go-cart, or something else that was part of the crazy dreams of a young boy. Dad was always there to help me strive for that crazy dream. To make it real, to try it, to find out whether that idea worked, and join me in that discovery. Dad was someone who was always there for you, be it a son, daughter, wife or mate.

There were countless times I'd have Dad trapped in the car, driving somewhere, somehow always late at night. He may have picked me up from Boy Scouts, and I'd be bashing his ears with arcane discussions about tanks, military paraphernalia or as a teenager, computers. He'd graciously allow me to talk, and be interested in what I was rabbiting on about. Thinking back, it must have been utterly exhausting to put up with, but he rarely complained or suggested I change the subject. But those trips also became moments to really connect and discuss many things of wider significance. Sharing a journey with Dad was always a learning experience. He was someone that I think everyone will agree was a wise and valued counsellor.

With me starting high school, it was Dad who suggested I should take a computer class saying "it's the way of the future", when the idea of it seemed abstract and an esoteric niche. When I wanted to buy a computer, he didn't just go and buy me one, he provided the opportunity for me to work at Scale and Engineering on holidays to earn money to buy one. Later, he gave Gaye the same chance to work at Smith's to earn some vacation money. In that, I owe my career and success to that suggestion of his.

Of course, success comes from endeavour, and Dad was the perfect example. In so many ways, from helping him in his workshop, to just observing how he worked and interacted with workmates at Scale and Engineering or Smiths, I learnt deep and empowering concepts. Of the value of keeping at a task, of how to respect and understand others, especially someone you might not agree with, or how to ask someone to do something. It gave me an appreciation of the value of planning, of working, of focus and self-discipline, and respect for others. I believe Dad gave that appreciation to many people.

But the thing was, while Dad was always ready with advice, and a definite opinion, he always could find the space in his heart to consider and respect an alternative opinion. He could always find the lightness of a situation. I remember when a neighbour (probably justifiably) complained about my band practice, Dad responded to the complaint mocking deafness with "What? What?".

With his diagnosis, what Dad ultimately taught me was courage. Dad faced lung cancer with the same sense of planning, of focus, of determination as every other problem he had encountered. But he did so in a way that did not make him embittered, or morose. He was very open about his illness. He didn't make that illness other people's problem, but he didn't hide or wallow in it. He was honest about his fears and after reflection, simply faced them and pushed on with that combination of vitality and determination he displayed to everyone who knew him. In memory of Peter, we need to be active in urging our friends and family to not smoke.

Dad had a sense of adventure that really showed when he travelled. I remember when Mum and Dad visited New York for Jill and my wedding. On the first day he jumped on the subway system, and chose random subway stops to see parts of New York. Nowadays New York City is a very safe city, but of all the stops he could have chosen, it managed to be East New York, the last surviving ghetto, making Harlem look good. But in classic Peter fashion, he had to have a chat with some local folks, being the only white guy, let alone Aussie, to visit for probably some time, before jumping back on the subway.

As Dad was ready to admit, he didn't receive a great amount of formal education, but for Gaye and myself, he was a teacher of something far more important: life skills. I believe there are many people in the room that will attest that he was as helpful to others as us in understanding how to deal with a problem, how to stand by your mates and family, how to appreciate and care for people, how to understand what the right thing is to do, and to do it properly. Thank you Dad for being a teacher, a joker, a truth teller, a sounding board, and an inspiration. Your memory and love will be with us forever.

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The passing of Peter Smith (8/4/1943 - 29/9/2011)

Leigh — Thu, 29 Sep 2011 10:50:47 +0000

My father Peter Smith passed away this morning at 10:37am at Kalamunda hospital. Thankfully I was able to be with him, my sister Gaye, and mother Dorothy at the time of his passing, which was peaceful. His condition had deteriorated very rapidly and thankfully this kept his suffering to a minimum. Thank you all for your kind wishes.

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Createasphere conference

Leigh — Thu, 22 Sep 2011 04:43:46 +0000

A heads up that I will be on a panel at the Createasphere Digital Asset Management Conference entitled Is Your DAM REALLY Ready for Audio & Video Files? This will be a great opportunity to discuss some of the work that Imagine Research has been working on over the last year.

Beat Tracking References

Leigh — Mon, 27 Jun 2011 17:10:47 +0000

Here are a set of references that I cite in my CCRMA MIR workshop presentation at Stanford University this week.

Authors:

Leigh Smith

CCRMA MIR Workshop notes

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Yèkèrmo Sèw

Leigh — Mon, 07 Feb 2011 20:10:04 +0000

I had the wonderful opportunity to work with some really talented and funny guys while at IRCAM. One outcome of this was some jamming and recording in a small jazz group with Juan Jose Burred, Gilles Degottex and Pierre Lanchantin. Here is our recording of Yèkèrmo Sèw, a piece written by the Ethiopian composer Mulatu Astatqé.

yekermo_sew.mp3

Fixing a Roland PC-200 MIDI keyboard controller

Leigh — Fri, 21 Jan 2011 19:34:33 +0000

Continuing in my series of keyboard repair blogs, I recently bailed an old Roland PC-200 keyboard out of storage. This old guy is just a 4 octave MIDI controller (no sound generator), but it fit the bill for having a reasonably sized polyphonic keyboard for a NYC apartment. Unfortunately it had long ago developed a problem with an F# key no longer working.

While there are newer controllers with many more buttons and polyphonic aftertouch, it seemed such a waste to replace it just because one key didn't work. After a little net research, a problem with many keyboards is that the carbon contact pads glued onto the rubber deteriorates. Replacements for these are available, but this was not a solution to the problem in this case.

I opened the case up and removed an octave worth of keys. The keys are ingeniously held by a spring, which is removed with a pair of needle nose pliers, and the keys lift off. The PCB has a molded rubber conductor strip which sits into holes on the circuit board, one strip covering an octave. To lift the rubber strip requires removing an octave set of keys. The white keys are numbered both by the chromatic name (A, B, C etc), and also the order in which they should be removed and replaced.

Lifting the rubber contact strip revealed the cause of the problem.

In manufacture, a pad of carbon is deposited onto the printed circuit board (PCB). This carbon pad contacts with the small carbon dot embedded into the rubber. There are four pads per key, the time difference between the rear pads conducting and the front pads conducting allows calculation of key velocity. Testing each pad with a multimeter showed a resistance of 60 Ohms, except the failed key, which no longer conducted.

To fix the deterioration of the carbon pad, I found an online supplier of conductive carbon paint. This comes as a 30g bottle with a paint brush.

The carbon paint was tested on an old circuit board first, painting between two metal contacts that I scraped bare. This requires painting a coat, then measuring the resistance with a digital multimeter, and repeating. Of course, as the carbon builds up, the resistance will drop. After several coats, the resistance of the damaged pad dropped to 94 Ohms, which when I tested with the key reinstalled, worked perfectly.