metasynth

I've used it.

I don't think there's an octave-scale repeating requirement.

It is non-real time. But that's because it's not for "performance". The
name is a bit of a misnomer: it's not a traditional "synth."

Have you ever heard of Xenakis' UPIC system? The one where you can draw
shapes on a page, and it converts them into wonderful (or annoying,
depending on your POV) glissandos and sudden blasts of sound, etc? Well
that's basically what it does.

Or you can scan in photos of your doggie and have it somehow interpret
them as sound, etc, etc.

Like any tool there are two sides: first, the "most obvious" stuff that
one can do. Lots of glisses in this case. It's easy to dismiss
Metasynth from this angle.

But if you get into it (I haven't really gotten deep into it), I think you
can do some cool stuff, including microtonal things. Some of the demos
that come with it show its versatility. All kinds of beautiful play with
timbre can happen.

But it's definitely not for a live performance paradigm.

Perhaps the name "metasynth" comes from the fact that you could use it to
construct scales that you could load in as sample banks in another
synthesizer. Hence it can be a Synth of Synths, so to speak.

cb