One of the interesting developments in rock music as the 1960s gave way into the 1970s was the diversification of styles. The loosely connected genres of folk rock and psychedelic rock had made a case for popular music in general and rock in particular to be a medium for genuine, grown-up artistic expression, rather than disposable entertainment for teens; but once you say “this doesn’t have to be like that“, you invite people to imagine all sorts of different ways it could be.
Folk rock and country rock singer-songwriters used the medium to examine tradition or social roots, critically or uncritically. Glam rock took the popular acclaim and youth appeal of earlier years, teased out the sexuality, and made it a bit more ambiguous. Blues rock gave way to hard rock if it still cared about being sexy, metal in slow and fast flavours if it went for other moods. Progressive rock groups explored just how far you could stretch the rock format, cramming in tools from classical or jazz as necessary to broaden the field available to them.
In a decades-early preview of the musical fragmentation we see today in this Bandcamp age where nobody has to listen to exactly what everyone else is listening to and it sometimes seems there’s more microgenres than musicians, the experimental wings of rock music ended up creative bands with astonishingly distinctive personalities. Oh, sure, you could sort them under one broad umbrella or another, and there were plenty of me-too groups out there inspired by others sounds, but within prog (for example) you’d never mistake Jethro Tull for Yes or King Crimson for Genesis.