I didn’t implement the tempo change in that particular video — only the track one fader. So, all you are actually hearing in the video is bits and pieces of the audio on that track being destroyed (though I could see how that would impart apparent pitch modulation).

You can change tempo via MIDI, but with the 2880’s tempo shifting in normal recording modes, you are limited to half step increments, which sounds kind of awkward (although you can use it for gated arpeggio effects and the like). I sort of wish the tempo slider would always behave like it does in the constant tempo mixdown mode, because I could then successfully create some Boards of Canada-esque sounds.