Hello,
I have put together a system with an SL880 as the main keyboard controller, and as the "front panel" on the beast leaves a little to be desired (I got it for a good price and I like the keybed), I was hoping to create some tools in PD that would modify an incoming MIDI stream.
I am interested in working with alternate tunings, and as such would be interested in any tools for PD that would handle "on-the-fly" retuning of a MIDI stream. From what I have seen of other implementations, the MIDI stream needs to be split up into different channels, where each channel has a different pitch bend assigned to it (or they could be doled out in a round robin fashion). Anyway, the point is to translate the incoming MIDI, and based on the current tuning system selected, and produce a multi-channel MIDI stream with pitch bend info to effect the tuning.
From working with the program 'scala', the definitions it has for what it takes to create a "keyboard map" for a particular tuning system would be a good place to start. While this is not a complete description, the file contains info to define a range of MIDI notes to translate, the base reference MIDI note number, and the frequency that is produced by the base reference note. There are other things that allow the "removal" of keys from the MIDI stream that are not used in the particular keyboard map.
Thanks,
Mike