Saturday
Jan232010

MORE OF A STRETCH

Since writing the journal entries below, with their emphasis on time stretching sound, I've been informed (tip o' the Hatlo Hat to Brian McLaren) of another excellent time stretching program.  This one is optimized for extreme time stretching - that is, time stretching from, say 5 to 1 million times the length of the original.  It's FREE, it's for Windows and Linux, and it's by the young Romanian programming whiz Nasca Octavian Paul, author of the free, very deep and useful (and microtonality capable) ZynAddSubFX software synthesizer.

This program is called "Paul's Extreme Sound Stretch" and can be found at http://hypermammut.sourceforge.net/paulstretch/.  I've tried the program out with a number of sounds, and the results are VERY nice.  There are a number of settings too, so tweakers will be very happy with this program.  Like Harry Partch said of one of his instruments, "It does only one thing, but that thing it does very well, indeed."  I especially like the readout on the "Stretch" parameter - it tells you how long your stretched time file will be.  I loaded a .46 second recording of some starlings recorded a few days ago in Texas by Catherine into it, and in the most extreme "Hyperstretch" mode, the readout said that the sound would last 1458 years 237 days.  Given my interest in impossibly long durations, you can understand how the idea of this tickles me. 

So if you're at all interested in sound design (or just plain having fun with sound), you should add this little puppy to you collection.  Highly recommended!

And by the way, for users of ZynAddSubFX, it's just had a major upgrade and revision, and it's been greatly improved.  Here's the link: http://zynaddsubfx.sourceforge.net/. Enjoy!

 

Sunday
Jan032010

HAPPY NEW YEAR TO ALL! - THAT'S A STRETCH, part 1

 

Here's a months worth of blog posts, all at once. I've been busy, as you'll see below. Including converting my PhD dissertation from academese into something more like reading, and preparing it for publication by Lambert Academic Publishers in Germany. More on that here soon. But for now, I'd like to begin with a quote from Nicholas Slonimsky, who in 1980, I had the good fortune to interview. (Info on the great and wonderful Nicholas Slonimsky: http://en.wikipedia.org/wiki/Nicolas_Slonimsky.)  Here's the quote - it says it all:

In the past month, I've been finding some interesting sounds, and one of the first things I've been doing with them is trying to extend them, or stretch them in some way. In early December, we made a trip to Melbourne, and as a treat to ourselves, stayed at the Shizuka Ryokan in the Victorian spa town of Hepburn Springs. This is a genuine Japanese-style Ryokan (country inn) complete with Zen garden, beautiful Japanese cuisine (the Kyoto-style breakfasts are a treat), spa tubs, and a completely peaceful environment. No tvs or phones in the rooms, and no cell-phone reception or internet either. To "unplug from the Borg," as I called it, even for a couple of days, was really lovely. The website is www.shizuka.com.au for those of you interested in checking it out. While there, we not only went to Hepburn Spa for the amazing mineral baths there (just a few hundred meters away), we also availed ourselves of the smaller, but still luxurious spa-baths in our room. And here was a delight - while draining the spa-tub, it made the most amazing gurgling! I even broke my vow of no digital technology for the time there, and whipped out my little portable sound recorder and recorded it. Here's the sound, all 2 and 1/2 minutes of it:

 

 

The sound of a spa-tub draining at the Shizuka Ryokan, Hepburn Springs, Victoria

 

A few days later, as we were leaving Melbourne, we spent the morning at the Melbourne Zoo, enjoying their new ocean exhibit. If you're in Melbourne, do go - it's marvelous. And whoever did the sound design deserves an award. Wonderful. Catherine took some pictures including this one of a peacock:

 

 

 

Peacock photographed at Melbourne Zoo, early December 2009, by Catherine Schieve

 

and then showed me how the zoom works on the display of her camera, zooming in on the central feathers at the base of the peacock's tail. I immediately thought - "Oooh, that would make a good score for something!" I thought of Nicholas Fournel's free AudioPaint program (http://www.nicolasfournel.com/audiopaint.htm) which allows you to use graphics as a "score" to play a sample, and which also allows you to use Scala files to play those samples on any microtonal scale you want. It occurred to me that the peacock tail closeup might be a neat score to spread excerpts from the gurgling around in an interesting manner. Why? Who knows why these juxtapositions occur? They just do.

 

On returning to Wollongong, other things happened, and I didn't get around to listening to the Ryokan gurgle recordings for a while. Finally I did, and also treated the peacock closeup with a graphics program so that the majority of it would be black (ie, silent) making a score for use in AudioPaint.

 

Peacock tail photo closeup treated with "tone-curve" plugin to get musically useful score

 

I had already decided that if I was using the Ryokan gurgle sample, I didn't want it played more than one octave higher or lower than the original, so I set AudioPaint to play over a 2 octave range (you can set any range you like), and that I would have the samples played in Erv Wilson's 64-note Euler Genus microtonal scale. So two octaves at 64 notes/octave = 128 notes. I made my Peacock Tail Score 128 pixels high. (Again AudioPaint allows any combinations of scale size versus pitch range versus picture size.) One of the neat things about AudioPaint's treatment of samples is that, like an old fashioned sampler or reel-to-reel tape recorder, lower pitches play samples slower, and higher pitches play samples faster. This means that if there are 128 possible pitches, each one will be playing the given sample, as a loop, at different speeds. You can get quite interesting time dispacements of gestures from your sample in that way. If you're using a long sample, like the Ryokan gurgles, with lots of gestural change in it, this means that your visual score should produce quite a variety of gesture and transposition. And it does. Here's the completed 5 minute piece - "The Ryokan Gurgle Processed by Peacock Feathers." Enjoy!

 


 

Warren Burt: The Ryokan Gurgle Processed by Peacock Feathers - Dec 18, 2009

 



Sunday
Jan032010

That's a stretch, part 2

Christmas time was upon us, and so out came the Christmas decorations, including Pengie, our inflatable Christmas Penguin. Part of Pengie's garb is a $2 Christmas tie, which plays a series of chopped up Christmas songs in full 4 bit glory. Unfortunately, the tie is showing its age, and the battery is going, and it sounds even squeakier than when new. However, closeup recording seemed to disguise the wavery warbling quality the weak battery produced. Here's what the tie sounded like this year (who knows what it will sound like next year, with further battery decay?):

 

 

Christmas Tie 4-bit sound maker recorded closeup

 

And here's a photo of me on Christmas morning wearing the Christmas tie, with Pengie and our tiny live Christmas tree (which normally lives in the back yard, without tinsel), and a host of holiday jolliness spread around the tree.

 

 

Warren Burt and Pengie on Christmas morning 2009, photo by Catherine Schieve

 

One of the first things I do with found sounds these days is to time-stretch them, hearing what they sound like when expanded. Back in the "old days" of the late 60, early 70s, there was only one way to time stretch sound without changing its pitch - a device called the "Springer Unit" which had rotating tape heads which allowed you to, to some degree, fragment and reassemble the fragments of sound, stretching the sound somewhat. I remember when I was a graduate student at UC San Diego, the department had one, but it was always broken, or breaking down, and students weren't allowed access to it anyway, so the idea of time-stretching sound then was pretty much just a dream, expressed in theoretical essays such as Steve Reich's "Slow Motion Sound," or in elaborate (mostly unsuccessful) experiments involving slowing down a tape while using an analog frequency shifter to transpose the sound up the required amount. Now the situation is vastly different. There are many software tools which allow you to time-stretch sound in many different ways. Most of them rely on some form of granulation (a way of chopping up a sound into tiny pieces and reassembling them on the fly), but they all sound different. Just off the top of my head, I can think of 7 programs on my computer that do time-stretching in one way or another: AudioMulch's Bubble Blower; Plogue Bidule's Looper; Adobe Audition's Stretch(process); Reaper's Elastique time-stretching; the many different time-stretching routines of the Composers' Desktop Project (whose wavecycle processes offer a unique method of time stretching - and hats off to Trevor Wishart for developing those!); and in the realm of software synthesizers, Linplug's CronoX, and Camel Audio's Alchemy both offer different ways of stretching samples in time and pitch. So the question these days is not "can we stretch a sound?" it's "which time-stretcher will give me results that interest me?" All time-stretching algorithms produce artifacts - in fact, the very notion of "natural" time-stretching is a contradiction in terms. What fantasy of yours corresponds to what you would like to call a "natural" sounding result to a totally artificial process? Nonetheless, some of the results of time-stretching sound more "mechanical" or "electronic" than others, and depending on the purpose your sound is intended for, you might prefer the results of one method or another.

 

Naturally, having recorded the Christmas tie, I tried stretching the recording in various programs. The program that gave me results I liked best, for this sound, was CronoX, a very nifty software synthesizer that not only allows you to stretch sound (to extreme lengths, too), it allows you to set the amount of duration stretching that will occur at different pitches, AND will allow you to then tune the whole thing into some microtonal scale. So here's the Christmas tie recording, stretched and doubled pretty extensively, into a 4 minute sequence.

 

 

Warren Burt: A Stretched Christmas Tie, December 25, 2009 - duration 4 minutes

 

I think it's pretty neat how a cheezee 4-bit chip can make a lovely sequence of bell-like, festive holiday sounds. And if you listen closely, and slowly, you can still hear the Christmas melodies coming through. For those of you tech-minded, here's the faceplate of CronoX with the settings used for this recording:

 

CronoX faceplate with settings for stretching the Christmas tie recording

For each key pressed, there are 2 copies of the recording playing - one stretched to 4.03 times original length, the other to 4.07 times length. The "time-track" (how much a sound is time stretched at different transpositions) is set to .63 for one layer, and .61 for the other - this means that a one octave pitch transposition down will only result in an approximately 1.3 times time stretch, as opposed to the normal 2x we're used to with tape recorders (for those old enough to remember tape, that is!). The keyboard is tuned into a 23 note just-intonation scale (not shown in the picture), so if the "key" of middle C is pressed, the sound will be at it's original pitch, but a "key" of C two octaves lower than that will produce a pitch just a little bit more than one octave below the original. The "chord" option in CronoX is used here, with notes (descending from middle C) of C, F Ab and C pressed. This means there are 8 different versions of the Christmas tie recording being played (2 per key with 4 keys pressed). This sound is not looping, so when the recordings reach their ending, there is silence. The almost 4 minute duration of the piece was determined by how long the slowest version of the recorded sound took to be played.



Sunday
Jan032010

That's (not) a stretch, it's a bunch of bugs - part 3

A couple days after Christmas, we went to our local National Park - Minnamurra Rainforest. Catherine had been the week before, and said that the lyrebirds were singing up a storm, so even though I knew it was Christmas holidays, and the park would probably have a lot of noisy visitors, I decided to pop my little portable digital sound recorder into my handbag, just in case. When we got to the park, I realized, as soon as we opened the windows, that recording lyrebirds was out of the question. Not because of humans, but cicadas. The cicada, which sings its noisy song in the summer, can be quite deafening if heard up close. If an entire rainforest is filled with them, all singing at once, the sound is incredible. Even though there were, as I thought, a lot of people there, I was able to find stretches of up to a minute with no human sounds present. I brought the recordings home and tried stretching them in various ways. None of the methods of stretching contributed anything to the sound. The sound of thousands of cicadas was sufficient on its own. This two minute segment cross fades three recordings - first a recording made above the main cicada action, starting with the (normally) dominant sound of the Minnamura river - the cicadas fade in here, taking over. After about 30 seconds, a recording made by the river, but lower down, in the middle of the cicada action, still has the growing and decaying sounds of the cicadas. This lasts about a minute. The final 30 seconds is made with the microphones pointed up right into a grove of trees full of cicadas going full tilt. Even though this was made only a few meters from the visitor centre and the outdoor cafe, no human sounds are heard. The cicadas are just too loud, and continuous here, for anything else to get through. To get the full cicada experience, play this one LOUD.

 

 

Three cross-faded cicada recordings made 27 December 2009 by Warren Burt, Minnamurra NSW Rainforest park

Sunday
Jan032010

Perhaps More Conceptual Art than Anything Else, Except That The Music Sounds So Engaging

A lot of my composing work over the past year has been using data from various mathematical things as a source for making music. Finding a clever way of realizing those numbers into sound is part of the fun of composing like this. Is there some kind of unique gestural activity hidden away in this sequence of numbers, and is the music I'm realizing with this able to show that uniqueness? These are the kind of questions that usually occupy me.

 

When I'm using, for example, a chaos equation, or the digits of pi, or other kinds of generated material for data, the implication is that the equation could generate new data forever, and the length of the piece is simply a matter of where I chose to hit the "stop" button. But there are some sequences that do have a finite length - they're just very very long. For example, these days mathematicians are continually discovering prime numbers which are longer than any discovered before. The current longest prime, as of today - 3 January 2010, is 2^ 43112609 - 1, discovered on 23 August 2009. It's 12, 978,189 digits long. So, although long, it's not infinite. Here's the website for those of you interested: http://www.isthe.com/chongo/tech/math/prime/mersenne.html#largest.

 

Another source of information is strings of letters - these can make very interesting patterns. As Chris Mann points out, we call these patterns "words." If one could turn a text into a string of letters and read those letters out one at a time, converting them into numbers, this would be another source of information with its own unique probability distribution, that of the distribution of letters in the language you're using. (The old nonsense phrase "etaoin shrdlu" is a list of the frequencies of the 12 most used letters in English. Google it for a lot of fascinating trivia.) One of the things added to ArtWonk version 4, was the ability to do just that, in a number of different ways.Many people have done letters to numbers to notes conversion in the past, not just the BACH or DSCH or ASCH of classical German composers, but more extensive use by composers such as Jackson MacLow and others. But I don't think it's been possible to do this with a large text, easily and in real time, before. As a source text, it occurred to me that an ideal one would be James Joyce's Finnegans Wake. After all, it's a very long text, and it's on-line (http://www.trentu.ca/faculty/jjoyce/F1-1.htm), and it's got just about all of human history contained within it. Plus, Joyce's continual use of puns and neologisms sort of guaranteed that the string of letters would have something other than the usual English "etaoin shrdlu" distribution. (Although I haven't investigated that - I'll leave that to the Joyce scholars!) I converted the first 60 pages of the Wake into a string of letters (no punctuation or spaces). It was just over 100,000 letters long. On the basis of this I can estimate that the full 645 pages of the Wake would be just over a million letters long. Not quite as long as the world's largest prime, but enough to keep life interesting for a while.

 

Then it occurred to me - why not do both a once? Back in 1997, I'd done a couple of pieces with the digits of Pi and the digits of the square root of 2 - Pi controlled music in one channel and Root 2 controlled music in the other. I could do this again, but here, my two sources of information would be very different - so why not have different kinds of music for them?

 

And so, Ladeez and Hermorphrodites, for your entertainment and amusement, a brief excerpt from

 

FINNEGANS WAKE VERSUS THE WORLDS LONGEST PRIME!

 

 

Warren Burt: Finnegans Wave Vs. The World's Longest Prime - first 5 minutes

 

This might be more of an excursion into conceptual art than anything else, except that the music here sounds so engaging. The stately bell like sounds in the left channel are produced by the digits of the worlds longest prime controlling the Alchemy softsynth which is playing an additive synthesis timbre made up of the first 10 prime numbered harmonics (and no fundamental) on a just-intonation scale of the first 10 prime numbered harmonics. Pitch (each harmonic in its proper octave), duration, loudness are all controlled by the digits of the world's longest prime, appropriately scaled.

 

The demented pseudo-folk music in the right part of the stereo space consists of accordion, ocarina, viola and tabla (substituting for bodhran) samples in the Wusik sampler playing in a 13 note scale which is prime numbers 3, 5, 11, 17, 31 and 41 treated as harmonics and subharmonics (with 1/1 left in for good measure). The data source here is the first 60 pages of Finnegans Waken each letter being interpreted as a number between 0 and 25. Each instrument plays over 2 octaves in the 13 note scale, with durations and loudnesses also controlled by the numbers produced by sequencing through the letters of the Wake. Each line starts the sequence at a slightly different place, so the right channel music is also a kind of pseudo canon.

 

The left channel music, slow and stately, also exists in a kind of stasis - its type of activity doesn't change a lot. This is to be expected - the digits of a prime number in the long term are very close to an evenly distributed series of random numbers - in the long term, there's probably an equal chance of any of the specified durations, pitches, etc. happening. The right channel pseudo-folk music, however, is produced by a decidedly non-random series of letters - the letters of Finnegans Wake - and there will be all sorts of surprises, as Joyce repeats, puns, and collides words together.

 

(And as a smart-alecky musicological note - of course, some mathematician is going to discover a new longest prime any day now.  In that case, the title of this piece will become "Finnegans Wake Versus the World's Second (Third, Fourth, etc) Longest Prime."  I'm not going to make even more work for myself by trying to keep up with every advance in mathematics!)

 

The excerpt here is only 5 minutes long. My crude guestimate of how long it would take to play the entire piece was originally just over 25 days. However, that was before I slowed down the tempo of the left-channel music. So now, I guess the total length would be several months. In the interests of good taste, and download bandwidth, I'm limiting this excerpt to 5 minutes. However, if any museum curator is reading this, and would like to have the piece installed as a sound installation, just get in touch. For an appropriately large fee, I can manufacture as much of this as is required.