Naw, man, Barret likes jazz and soul. Folk, O53wewL8nT8#t=3m55s stuff like that. He's soft inside. Can't link yt before atm so c/paste.
I can definitely see Cloud being a top five guy with an untapped enjoyment for slower and thoughtful rock, as of the start of FFVII his mind's kinda abstract. He wouldn't care for finding an exotic sound best suited for him and any junky alt rock song would tickle his tastebuds if the melody's good. His true tastes, which he never realizes until after the story, are more chillaxed.
But he passively respects 80s rock a lot, which happens to be Zack's favourite genre.
Aerith liking Muse like the other person suggested and less super mainstream bands would be a good idea, she's a more established and self aware personality than Cloud at the start of FFVII. They're mainstream still, just not borrowed from popular taste.
Red XIII likes I970aWYDCYI stuff like this and HvdNI00b1V8 abstract synthesized music, techno, especially stuff like the latter. Things that lay a relaxing foundation for deep thought.
Sephiroth likes classical. Piano, organs, orchestras. And maybe a secret fondness for Disney songs, he lauds their composition and looks to them as something he missed from his childhood. He doesn't realize why he likes them.
Yuffie being raised on traditional and wanting to be a k-pop member is perfect.
Cid likes anything boisterous from Eminem to thumping industrial to 70s rock, even some country.
I just imagine Don Corneo listens to Oh Yeah by Yello on endless repeat when he's alone...and also when he's not
I'm going to lay someone with this song playing sometime and she's going to ask "why is this song playing?" reeling