karaoke instrumentals

[8sumint]

maybe someone knows about this...

let me start with a tangent. i happened to be thinking about the RYTHEM tune "気球が虹を越えた日" off their 2006 album Mugen Factory cause it has this great move in the chorus --
cho: | G | Bm | Em | D G11 | C ... basically doing a V->V7 instead of your ii->V7 to IV.
which i think is really clever but also i'm not sure if it's real?

a decade after their 2011 breakup, in 2021 they started posting to their youtube channel again and did a bunch of self covers, and when they did this tune, Yui played it on keys and she does it as a ii-V every time.... and she's credited as writing the original track so maybe that's the end of that? why is it like that then? did Chokkaku put that in? they don't even really do it every time -- it's for sure Dmaj in the first chorus but the second time around they at least sound like they want to sing it as Dm (which is fine). It would be interesting to see what it sounds like when they do/did it live, but I'd have to buy the bluray or something.

(subtangent, they also put out a new album that i didn't find that amazing but the single, 星風, is pretty nice. they got satoshi takebe back to do it (of 桜唄, some others) and put out this special-edition-dvd-core behind the scenes video that is fun if ur into that sort of thing)

anyhow, in search of more evidence on this, I came across this cover on niconico which is actually pretty good. it has this great midi backing track that does that pitch bend guitar thing that really gets me. as for the chord progression question, he sings it kind of inconsistently but in a different order than the original track so. idk. lol

but (punchline) where did /that/ track come from? who sequenced it?
where can i find contemporary midi instrumentals of 2000s jpop songs to listen to?