I find writing DDR stepcharts for songs a really fascinating way of taking them apart and seeing how they tick. From a musical perspective but also as a kind of window into the recording environment.

Did one for a recent (2022) anime's ED, and unlike what you'd normally expect these days where the track is perfectly quantized, it had a number of irregular measures here and there. Doesn't sound live. Maybe it was produced in high COVID times and had to be cobbled together from home studios?

Tackled one from 1987 this morning (the first Dirty Pair OVA's spectacular Bond-inspired OP) and it's all metronomically on beat except...for one measure in the intro that has an extra 16th in it. This is the sort of thing that passes without notice for the listener but is a tremendous problem for DDR. In any case, listening through it a few times, sounds like a mistake so expertly swept under the rug by professional musicians that the producer thought sure, this is good enough for the album. It's an excellent performance by any measure other than "does this cause fits in Stepmania?"