"music theory aware"? Like...it snaps sequences to scales like every other decent sequencer? I can't actually tell why this is useful from the front page description.
Nope! With those systems you have no way to input accidentals. Here, notes are entered in scale degree, so if you say "4 5 6" you get the 4th, 5th, and 6th scale note, every time. If you later want to transpose to Eb Pentatonic, everything remains musical. The arp can also tranpose by scale notes instead of just semitones too.
Also, there's quite a bit more, all in the docs. There's a ton more there.
What you've just described after "Nope!" is exactly what I mentioned in my post, which is now downvoted I guess. Many many sequencers let you ask for "4 5 6" and adjust for any scale you want. What are you claiming is new here?
Those sequencers do not include Ableton, the Monomachine, Bitwig, Logic, or any that I have experience with. They all use force to scale mechanics that make accidentals impossible.
I suspect Numerology might. I've only seen semitone transpose in most arp implementations, never the ability to work within scale notes. I've never seen an arp that can walk across chords and probabilistically invert them.
The Cirklon had a lot of great ideas including some things like random step transpositions and variables - but generally, in DAWs, it's not something you have access to. Nobody's even tried to get something like Electron parameter locks going, which is a shame, because they are awesome.
I don't have enough karma or levels or superpowers to down vote anyone. I have no idea how this website works in that regard.
Not if you're moving from one kind of scale to another, as you've said you can.
6 7 8 are functionally different to 1 2 etc in an eight-step key.
In fact they're different across different 8 step keys. 6 7 8 in Phrygian are structurally different compared to 6 7 8 in Minor, even though they're the same pitches.
Chords and melodies that use them do not have the same shapes - not because of accidentals, but because they're fundamentally not the same thing and they move through the scale space in different ways.
And in harmonic minor 6 7 8 ascending and descending are different - not just made different with accidentals, but contextually different.
Meanwhile pentatonic melodies can have a pentatonic harmony, or they can have harmonies in other scales and modes. How do you know what "4" is supposed to mean if you're not aware of this?
Of course you can trivially map Thing to Other Thing in Python, but if you don't understand these relationships you're destroying the musical meaning. This is fine for vaguely ambient noodling, but not for building a genuine theory-aware sequencer.
In music theory you don't just play with numbers, you play with style conventions, context, and meaning - and solving that is a much harder problem than you've managed here.
Also, there's quite a bit more, all in the docs. There's a ton more there.