Got around to watching the whole thing, and it brought on a tidal wave of nostalgia
It clarified a few things about the sound of the early stuff, and why they tended to use that rapid arpeggiation instead of chords (it was down to the available polyphony).
It was also cool to see Unreal, Unreal Tournament and Deus Ex get a mention in there too. I still have those original music files. They were in a crossover period. CD audio and even MP3 was available at the time I think, but the tracker music provided longer sound tracks and even dynamic/situational music which wasn't really feasible with wave audio.
Tracker music had the useful characteristic that it's file sizes where "logarithmic" in nature, where regular sampled audio is linear. Once the sound samples were stored in the tracker file, the tracking data was much smaller and repeated patterns further reduced file sizes of longer pieces. Total song lengths could be 10s of minutes while being less than 2MB, and the sound wasn't compressed or low sample rate. Super impressive at the time when games were struggling to fit all the needed data on a CD, and downloading MB of game content was out of the question.