Music 171 homework 7

Cascading tuned delay

This is an effect that sometimes showed up on "digital delay" devices in the early 1980s. Anything that goes into the effect comes out as an arpeggio (a quick, overlapping sequence of pitches) that can either be used to decorate the original sound or by itself as an abstract-sounding musical cloud.

The network consists of a delay line (just a delwrite~) that is read out by 19 copies of an abstraction. The abstraction contains a delread~ and a bandpass filter (bp~ will work fine). Each copy gets a different delay and a different filter setting so that if you put a short sound in (for example) you hear the 19 filters in order of the delay times. In the example here, the delay times are just 17, 34, 51, ... (the multiples of 17) - of course, the number 17 is just a setting that you can change later. The filters are tuned to a whole-time scale, specifically, the MIDI pitches 72, 74, 76, ..., 108. (these are chosen roughly to span the formant frequencies of most vowels so that this setting works particularly well with speech.) The steps are as follows: