Using helmholtz~ , is it possible that filtering out the detected frequency and sending the (filtered) audio to a second helmholtz~ for pitch detection would result in an effective polyphonic pitch detector? For my initial experimenting with this, I hooked up a series of six helmholtz~ objects, taking the output from each to set a hipass filter with a cutoff frequency just above the detected frequency. I then send the audio input source through the filter and into the next helmholtz~ , with the hope that I have reduced the first detected frequency by enough that the next most dominant frequency will be detected.

The result with my electric guitar as input source was interesting; most of the time all six helmholtz~ objects output the same frequency. However, I found that if I played softly enough, I could get some of the frequencies to 'stick' at their previous values. It's kind of a cool effect in its own way, but not what I was going for, since my hope was to be able to trigger full chord changes.

I think maybe some of the problem may be my implementation, since I'm pretty new to pd, and I'm going to be playing with this a little more to see if I can get it working better. I'm curious though, if anyone else has tried this method before, and if I'm trying something that will definitely not work.