Some of you will already know the rm-repeated-pitches method. This finds repeating pitches in any or all voices of a slippery-chicken object and replaces them with other pitches from the current set. Of course what this is doing is ironing out some of the problems inherent to algorithmic pitch selection, and slippery chicken’s in particular.
For the Goldsmith’s project next month I’ve developed a related method called add-auxiliary-notes. This tries to deal with some of the static pitch structures that arise out of limited but extended harmonic fields. It analyses slippery-chicken voices phrase by phrase to find the most frequently used notes, then changes some of them (according to an activity-levels object) to auxiliary notes (up a semitone by default but any and varied intervals are possible). It’s already available on the SVN server so those of you who want it will find it along with documentation in the file slippery-chicken-edit.lsp after doing (update-app-src …)