harmoxen VS helio-sequencer

Now for your first question, I don't know about doing it with arduino, but if you manage to find resources to send simple midi messages, it'll be the same thing to send MPE messages as well. As to what messages you should actually send however, I used this to understand how to send pitch bend range information, and learned the rest from the spec and a bit of tinkering. You can check out the source code of my custom piano roll which uses MPE to send notes with arbitrary frequencies. The relevant parts are the setup_mpe method, which just has to run once in the beginning to setup the synth to which you're connected. The other ones are note_on and note_off. (sidenote: actually here I'm not using the least recent channel because I was lazy when I wrote this, but)

I downloaded this and played around with it a little.

I’m a little skeptical of something that ditches traditional music notation for piano roll, doesn’t offer any ways to reorganize sections of your song, and then gives you a bunch of tools for key signatures, modes, polymeter, and microtonal music. I’m trying to think of a programming analogy—it’s like checking out a new programming language that has dependent types, higher-kinded types and monads, and a borrow checker, but no strings or integers.

It’s really easy for those of us with analytical, mathematical minds to go diving into the more esoteric parts of music theory. Set theory, microtonality and alternative tuning systems, esoteric scales and cataloging all these different scales—but then you fuck up the basics or miss them completely. I noticed that the “major” scale is only available under its more esoteric name, the “ionian” scale, and then there are five different versions of locrian to choose from, not counting the ones outside 12-EDO.

https://github.com/helio-fm/helio-sequencer/blob/develop/Res...

Even with all these esoteric features, there is no such thing as, say, Eb. There is only D#. As programmers, we really want to normalize all our data so that it’s represented in exactly one way, but as a musician I like having both sharps and flats around. They’re convenient and make the music easier to read.

This is a neat tool for playing around with scales and tunings, but it seems like absolute hell to try and write music this way.

Not really a DAW (more towards a sequencer), and haven't used this software for a year+ to comment on its current state but we have Helio Workstation.

Helio is another cross-platform option, more streamlined and even more powerful.

Helio

Well if you don't want a daw you could try https://helio.fm/

Helio (version 3.8): Music sequencer, designed to be used on all major platforms

I love MuseScore and want a decent notation editor for my tablet, but pickings are slim, unfortunately. Most of the editors I find have abhorrent interfaces. I'd even be fine with a LilyPond frontend or something, rather than what I do now (Helio is truly wonderful and ticks my boxes, but can't produce notation).