2011/12/27 Stephen Tetley <stephen.tetley@gmail.com>

Hi Tim

More problematic is that FRP models hybrid (continuous and discrete)
systems. For me at least, MIDI seems essentially discrete - a stream
of control events. In MIDI files control events are twinned with a
time stamp so they can be played. Presumably events are instantaneous
in real-time interactive MIDI - not something I've looked at.

The events all feature a time stamp and my drum set produces lots of "CRTClock" events for synchronization. I didn't use the time stamps in my Java application but I would have to for recording/recognizing rhythms.

Working with an FRP system like Yampa might add a lot of complexity,
which admittedly you should be able to ignore

Yes, I'm a bit afraid of that.

but initially it might
be difficult to identify what parts are needed for a "mostly" discrete
system like MIDI. (If you are time-stamping MIDI events yourself you
will presumably need to sample a running clock which seems like a
continuous behaviour...)

Unfortunately I can't think of any systems in Haskell that are "more
discrete than continuous" so you might have to choose a FRP system
anyway.

I just had a glance at Peakachu. It seemed easier than Yampa to me. I liked the Program abstraction. Perhaps I can use this...

Incidentally, I've been working on a MIDI "animation language" for the
last couple of days based on the animation language in Paul Hudak's
book. I've wanted continuous behaviours to model modulating volumes
(crescendos, decrescendos) and panning, but I've found the work tough
going for modelling the note lists where I want the system discrete in
both input (specification) and output.

This reminds me of the Yampa based synthesizer from the paper "Switched-On Yampa". I just looked into it.

Best wishes

Stephen

Thanks
Tim