#i've seldom had to music theory before and just barely had enough knowledge to get here

[lilacchao]

oh this is super interesting! using heartbeat tempo adjustments instead of time signatures is clever, and makes sense for the game design - and i think i've come up with a plausible answer for the source of the tempos!

recipe for 15/8: start with 4 "seconds" (they're actually beats but who cares). split it into 2+1+1 seconds. first bit is in 4/4 time (120bpm). middle bit is treated as 3/3 time (180bpm), a triplet. they move the fourth 4/4 note from before to after the triplet. they cut off the final 0.25 seconds (last bit goes from 60bpm to 80bpm, aka 1 second to 0.75 seconds), giving you (2×12+9+12)/24 = 45/24 time so far (which simplifies to 15/8!!!).

they decide to confuse the player more on the triplet by stretching it out ~5% (180bpm -> 172bpm) so it gets cut off by the fourth 4/4 note (the third 172bpm becomes a bizarre ~200bpm because it gets cut off), and then adjust how much time the final note of the triplet should last by feel to an even shorter 234bpm before it gets cut off, because you want the player to feel rushed here (triplets already create that rushed feel, that's why waltz time is fun, the cut-off then exaggerates it a lot).

recipe for the "29/16" one: start with the above. speed the tempo up ~5% (120bpm -> 126bpm, 172bpm returns to 180bpm, 80bpm -> 84bpm). fiddle with the end of the triplet some more (hence 236bpm instead of 246bpm). cut off the final 0.125 seconds to make the player feel even more rushed (84bpm -> 102bpm). note that if they cut off the end before changing tempo (which would've got 29/16 pre-fiddling), it would be 101bpm, so it's definitely not 29/16, the order of operations to create it is wrong.

mother 3: so we have this system where you can attack in beat with the music for combos! no worries, it’s really simple and easy to understand! have fun :)

mother 3: this song is in 29/16