Bands that change their sound often

The sound is usually down to the equipment being used and very few bands just change their instruments or rig that often. The ever evolving style thing is a myth of progressive rock although Gentle Giant came as close to anyone. Their albums between 1973 and 1975 are all very different to me.

Joke suggestions are Genesis , Rush and Tull

King Crimson were never a traditional band and had a lot of line up changes that inevitably changed the sound , same with Yes to a lessor extent.

ELP don't get many mentions , but there are major differences in sound crossing from the classically eclectic debut in 1970 , the electronic approach of BSS in 1973 and then the more acoustic based Works Volume One 1977. Love Beach in 1978 , ELPowell in 86 and Black Moon in 82 also all sound very different. Mostly it was the same line up so some credit is due to them for attempting to evolve.

 

Pink Floyd? Granted they changed from the initial Syd psychedelic sound but I would contend that all their albums from Meddle onwards are pretty similar.