Quibble: by the standards of the classical music world, Paul McCartney is not a classical composer. He has help (at least) with the orchestration. Certainly he writes the melodies, but he has a collaborator (Carl Davis) who does the orchestration.
This may be true of Copeland and Byrne as well.
Since the classical world considers orchestration to be as much a part of composition as melody (perhaps even more so, in some cases), a composer who doesn’t orchestrate is, at most, a collaborator.
There’s a (perhaps apocryphal) story that’s told about Igor Stravinsky that illustrates my point. At some point in the 50s or 60s, when he was living in California, he was approached by someone at a major studio to score a film. He was intrigued by the idea, and mentioned a fee of $1 million. The studio was shocked at the amount, and said that they couldn’t possibly pay that much, since they’d also have to pay the arranger and the conductor. Stravinsky was hugely insulted by the implication that he could not orchestrate his own work (after all, Stravinksy was and is recognized as one of the grerat orchestrators), and walked away from the deal.
If you want an example of a genre-switching musician who moved to classical music, check out Mark O’Connor. A brillian violinist who made his name in country music, then went beyond that to classical (much as **Bela Fleck **moved beyond country to jazz, or whatever he calls his highly idiosyncratic music).
Beck is another one like that. Name any genre, he’s done it; often, a few different ones in the same song even.
Gwen Stefani went from pure, third-wave ska with No Doubt, to whatever shits-and-bananas she does now.
Omar Rodríguez-López and Cedric Bixler-Zavala went from punk legends At The Drive In, and have, album by album as The Mars Volta, unraveled into an increasingly incoherent mix of prog, jazz, and noise. (Deloused is still my all time favorite album though)
Incubus has gone from funk and a slight nod to hiphop(Fungus/Science), to pop-rock with a slight nod to prog(Halo2 soundtrack). Their all instrumental side project, Time Lapse Consortium, is a nice blend of jazz and funk.
Tom Morello went from Rage Against the Machine to his solo, acoustic, folk project of The Nightwatchman(very, very good btw)
Is it possible that no one has mentioned Little Richard? He went from being the most depraved rock & roller of the 50s to pure gospel (with some backsliding since).
Jerry Lee Lewis went from rockabilly to pure country.
Dion DeMucci went from doo-wop to Christian music, and recently to blues/country/classic rock.
David Johansen went from the pre-punk of the New York Dolls to lounge music as Buster Poindexter.
Jonathan Richman went from the surly punk of the Modern Lovers to his happy, childlike solo stuff.
John Lydon – from punk (Sex Pistols) to very different postpunk (Public Image Ltd).
Brian Eno went from the twisted avant-pop of Roxy Music (and his first couple of solo albums) to ambient music.
Van Morrison went from British Invasion to Celtic soul.
The Moody Blues’ first album was very much British Invasion style bluesy pop, after which they switched to cosmic chamber-folk-pop.
Donovan went from imitation Dylan to Celtic raga pop.
Jethro Tull started out as a quirky blues band before switching to cerebral prog rock.
Sorry to nitpick, but going from rock to pop or form heavy rock to death metal isn’t “completely switched”.
Also a gradual change in a long carrer is not the same.
A hypothetical example would be Cannibal Corpse doing country-western.
They used to play at the Friday night dances (very casual) at my HS in the early 70s. I was not yet in HS, but my older sister was. She remembers seeing them.
Yeah that was pretty much the intent of the OP, but people seemed to be enjoying themselves so I let it go. Although to be fair my examples in the OP weren’t the best. Ministry is who I really should have thrown out there. Their early albums sound every little like their later work.
I came in to mention one- Danny Elfman. As a young man, he had quite the punk edge (Perfect System, Capitalism… hell, the whole *Only A Lad *EP, I suppose), then progressed to more mainstream pop (although still smarter than most), and now he composes soundtracks almost exclusively. Remember, that doesn’t mean “got a song on a soundtrack”- scoring a film takes time and talent- I think he says it take him a 6 hour day to score two minutes of film…
And he’s been nominated for lots of awards for his scores.
The Beatles started off as a Mersey Beat group and evolved into Pychedelia,Paul Mc actually wrote a waltz after the band broke up,Mull of Kyntire and a kids tune,The Frog song.
