What am listening to? Long time musician here, just not familiar with untraditional scales. I assume 31edo but using Bach means you are ignoring 19 of 31 possible semitones- correct? Less? (I could imagine leading tones going in the opposite direction, or something)

To my ear it sounds like there are way more major thirds than there normally would be in a Bach piece like this... anything else I ought to be hearing?

Wendy Carlos Beauty and the Beast is my fav non 12-tet piece of music. It is in two scales she made up herself

https://www.dailymotion.com/video/x2j1gy2

Terry Riley's Harp of New Albion is awesome as well.

https://www.youtube.com/watch?v=k6tptdvQbos

Harry Partch - Two Studies on Ancient Greek Scales is so haunting https://www.youtube.com/watch?v=GglpEGSXpXo

I haven't listened to the piece, but afaik typically transposing existing 12TET pieces into microtonal tunings are taking the intervals in the original piece and applying them to scales in the new tuning, with some creative license/taste to embellish where it doesn't sound so good. So it's not ignoring or limiting any pitches to my (limited) understanding, other than the natural way that pieces written in a particular key/mode will skip over some tones in favour of others for harmonic or melodic reasons.

I would guess you're right but I'm not 100% sure! This channel is pretty responsive, you ask on the video.

This one is fascinating too - it's just intonation vs 12edo comparison. You can really hear all the beating in the harmonics in the EDO one.

https://www.youtube.com/watch?v=AgB4TrV57AU

Interesting, that sounds like music from some kind of medieval castle that somehow got stuck in a timewarp. I can't listen to it for very long but it sounded a lot better than I thought it would.