Wayne Freno wrote:
> 
> What are the best sources (hopefully free and on the
> internet! ;-)) for using audio files in granular
> synthesis?  So far I can only get the grain opcode
> to use a sine wave, but I can imagine mucho pontential
> with audio files!  Thanks!
> 
> Wayne Freno

Don't know of what internet sources there are, but you're really missing
out by not experimenting with natural audio as the source. Also, I
haven't been using csound lately, so I don't know what the opcode
parameter are, but a nice start is to take a sound file and do the
following with the grain stuff:

- set the playback speed for the individual grains to be either the same
as the original sample, or lower (most likely) or higher, depending on
what frequency spectrum you want the result to have
- set the parameters so that the granulated output will slowly traverse
the source file, but much slower than the original sample's playback
rate. (time expansion, basically)
- set the parameters so that the grain density is fairly high. By
density I mean how many grains, on average, are playing at any given
point in time. What I mean is you want overlap. Maybe 5 to 20 for
starters?
- Randomize the times a bit, either in at which point in the source file
successive grains are taken from, or in at what point in the output file
the grains are started.
   
The result of this is you'll get a time-stretched version of the
original file, but because of the grain density and built in randomness
(jiterryness?), it can sound much richer than the source. The perception
is one of slowly experiencing every nuance of the timbre changes of the
sound. I did this once with a cheap soundcard recording of a bicycle
bell, and the initial "clack" became a complex unpitched sound, and the
ringing of the bell turned into a delightfull, 10 or 20 second evolution
of timbre as the bell decayed.
 
I know this is a bit sketchy and maybe not self-explanatory. Hopefully
some one who knows the grain opcode will chime in.

Larry
  
--  Larry Troxler --  lt@westnet.com  --  Patterson, NY USA  --