I am wondering if anyone has attempted to create a risset rhythm using pure data. I found a 4-page paper detailing some of the mathematics involved .

(https://pdfs.semanticscholar.org/2de1/e9505baf81121d1622e0470d09cc48577f3a.pdf)

Is this possible?

Thanks!

There is an example Shepard Tone in 3.audio.examples --> D09.shepard.tone.pd which might be of help.

Not sure exactly what the difference is between Shepard tone and Risset...

Thank you so much! This is definitely a good starting point.

The algorithm for a risset rhythm is the same as the one used to create shepard-risset tones. Just change notes with a percussion loop and frequency with playback speed.

Strictly speaking our distinction between rhythm and tones is purely perceptional. Speed any loop up enough and you have a tone.

Awesome!

I have found the D09.shepard.tone.pd file, but I can't hear any sound... in fact any patch from the audio examples list with the output subpatch doesn't seem to play. I have tried clicking the in the db number box to change the value, but that doesn't work.

(I'm totally new to pure data... so I must be missing some fundamental knowledge)

Any help would be greatly appreciated. Thanks in advance

Have you turned DSP on? Top-right corner of the PD console.

DSP is on, and test tone works.

Patches I have created with dac~ have worked.

Does the number beside db in the output subpatch need to be greater than 0 and less than 100? Currently it is 0 and I have unsuccessfully tried to change it.

Thanks again.

Click the START message box to initialize the patch, then raise the DB level

Thanks for all your help! I was trying to input a number for the db level... I just realized I need to swipe up on the mouse pad to raise the level instead of typing a number.

Thanks again!

You can type into those number boxes too--you just have to press Enter afterwards.

@LiamG said:

Not sure exactly what the difference is between Shepard tone and Risset...

The original Shepard algorithm is stepped, chromatically I think, as in one semitone at the time. Whereas the shepard-risset algorithm is a glissando. Risset then applied it to rythmic patterns as well.