Meaning, bands that mix styles *within *the same song that usually would be totally separate. I think there are quite a few metal acts that mix something like classical, folk, and metal, like Opeth.
Back when I was a Christian in my college days, I really liked a band called Believer. They were AFAIK, one of the pioneers of mixing metal with opera music on their album Dimensions.
I’m sure there are plenty more, and of course it shouldn’t be limited to metal…
Queen’s Bohemian rhapsody is of course a clear example.
Thread over. No second place.
(Never mind. Misread the OP.)
I think Estradasphere is another band that really mixes things up.
Great name-post combo!
Anyway, another famous example would be “Stairway to Heaven.” Starts out as a nice little flute piece, and and up… louder.
Some Frank Zappa examples:
The Duke of Orchestral Prunes - Classical music with an electric guitar solo.
Orange County Suite - Rock and jazz, with some polka-esque music too.
Strictly Genteel - Classical music with dirty lyrics about garden hoses and microwaves.
Eat That Question - Starts out as a nice keyboard piece, then quickly moves to a full jazz/rock song
Neil Young went through a few styles in Buffalo Springfield’s ‘Broken Arrow’.
Jethro Tull does a bit of moving between the folk and the rock in a single song, like Minstrel in The Gallery or Heavy Horses
The Beatles’s “A Day in The Life.”
Chumbawamba - ‘Ugh! Your Ugly Houses’. Thrashing punk rock interpersed with ‘English Country Garden’.
There’s also a fair amount of range in Thick as a Brick and A Passion Play, though they’re both album length songs.