Ben Bradley wrote in message . ..

I'm trying to follow the thoughts... it appears what he wants is a
computer program that does with an orchestra what one does with a
synthesizer to imitate the sound of a musical instrument ("imitative
synthesis"). I suppose nowadays you could write a program that scans a
digitized audio recording and makes a patch (or orchestral score) that
somewhat crudely approximates the sound, but it could surely be
tweaked by hand/ear to make it better, or perhaps a synthesist (person
making a synth patch) would just start over and make something that
sounds better/closer. I doubt that having it do a mathematical
operation such as a fit a least-squares match of the FFT would make it
anywhere near the "original sound" as would a person experienced in
doing these things.

Well, maybe, I don't really know. I'd be surprised if some type of
math couldn't be rigged up that would do as good a job as a human.
It's all analytical, and actually not too subjective. It will either
sound like a jet engine or not, and since the computer will "know"
what a jet engine sounds like thanks to the FFT and differential
analysis, it seems to me this shoud be as easy as asking a computer to
come up with a number that adds to 7 to make ten.

It doesn't matter if it's in real time or not to me. It could take an
hour to process a minute long soundfile for all I care. And once I
get something together I can tweak it for better results, and it
doesn't have to be perfect. Again, this will be mainly a learning
tool.

But to make "arbitrary sounds" with orchestral instruments ... the
only thing I've heard that's anything like this is on Peter Shickele's
"Upper West Side" where he says something about hearing Vivaldi one
more time. The strings play throught the melody once, then they play
the beat of the melody with hip-hop record-scratching sounds. It was
hard to believe my ears. Is there a video? I'd like to SEE these
string players reproducing this speed-up-and-slow-down
record-scratching sound.

Hmmm, I've never heard this before. You're not talking about the
musical "west side story" I gather. Anyway, my guess is that it's a
simple dodecaphonic or maybe microtonal glissando performed with light
enough pressure on the bow/strings to emit that rosiny scratchy sound.
I keep bringing up this guy's name, but if you haven't listened to
any Ligeti, you really owe it to yourself to. His "Atmospheres" and
his "Harmonies (for organ)" are good starting points. His music often
sounds like Arbitrary sounds, and it's always produced with
traditional instruments. "Harmonies" is especially interesting. The
organ has to be rigged up to change the inner air pressure so as to
play microtonally. The low powered organ sounds like a giant whoosh
of sound, or the kind of still wonder you might expect an astronaut to
hear in his head. It mesmerizes and twinkles like distant stars or
complex microscopic schools of glowing plankton in the ocean at night.
In fact, a small bit of Atmoshperes was used in 2001: a space
oddessy. A lot of his music takes you into the moment, stops your
breath, and makes you question why no one else thought of it first.
He does this partially by emulating real world sound.



I would suggest that
you go to comp.dsp and set forth what it is you want to get
more specific feedback about it.

This is good advice.


Like MIDI output of polyphonic audio input, this technology is not
quite (actually nowhere near) ready for prime time.

If it was out and available on every supermarket endcap, I probably
wouldn't want anything to do with it! ;-) This interests me because
as far as I know, it isn't really done that much (the orchestration,
not the software), and certainly not the extent I want to take it to.




Bob

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