The Quietus review for SH lead me down a rabbit hole there and found this interesting quote from Karl's Baker Dozen writeup of favorite records. It's in reference to Burial's Untrue record and is something I've always wondered about Underworld's take on vocals as another instrument or sample to work with:
"There are a lot of parallels between this record and the roots of Underworld's inspiration. Film music. Taking sounds and songs and melodies from other tunes and fusing them together with other music in a completely different key. And it just has this dusty, beautifully dirty quality - like film noir through a dirty window. I absolutely love it. We took it to Chile with us, Rick and I, and played it in our hotel room and decided it was the best thing we'd heard in years. It inspired us to start writing there and then in our hotel room - music that went on to be part of the download-only records we did. It encouraged us to be a little less produced. It's an amazing soundtrack for what's going on around you. There's a link between these first three records - especially with James Blake - the way that the voice is treated. It was very exciting to hear the voices on the Burial record treated in such an unprecious way. Taking vocals as oscillators, as we'd always seen them, like another synthesiser that's capable of generating incredible noises. That in itself was inspiring." https://thequietus.com/interviews/ba...rite-albums/4/
I've often wondered if their process of cutting vocals up and putting in new contexts than original lead to them liking the weird off-key nature and organic/human-ness of it. I know there's probably been times that Rick fully replaced the music out from under what it was originally sung to, and sure that could be mess-with/edited to fit better, but it's also an artistic choice to work with. Karl also in the piece mentions really getting heavily into Dylan then, and that's been mentioned on here as a similarly purposeful artistic thing. IDK, probably second-nature at this point.