Interactive 'harmonic trendline' audition application

Published on Jan 23, 2018 Pi Synth

"Here is my interactive organ pipe auditioner, based on the 'trendline' harmonic fingerprint system described here - http://colinpykett.org.uk/parameter-e...

The usual waveform display, but I have hijacked the metronome to use it to display log/log harmonics.

The idea is that a very small number of parameters can accurately describe the harmonic fingerprint of the sustain phase of a note generated by an organ pipe. This thing - running on the Mac but again, the Pi Synth codebase so it will run trivially on a Pi Zero - lets me twiddle knobs and instantly explore the entire parametric space.

The methodology desribed by Pykett requires 4 floats to describe a pipe. I have modified this to add 2 more parameters that allow an individual harmonic in the fingerprint to be boosted or cut, which lets a single non-trendline outlier harmonic be correctly modelled. Also I have allowed the 'even harmonic cut' to be an 'even harmonic cut/boost'.

The six parameters are mapped to 6 MIDI CCs, and I can sit sit and twiddle. Tunelessly. But allowing A/B listening against a field recording to rapidly converge to an accurate setting for a given rank at a given note. Nice."