As the drug-fuelled experimentation of psychedelia waned after the Summer of Love, bands either went heavy, like Led Zeppelin, Deep Purple or Black Sabbath, or retained a spirit of musical adventure, marrying seemingly ill-matched sounds originally heard on Sgt. Pepper, Pet Sounds and Frank Zappa's Freak Out! and adding some symphonic or classical flourishes. Add a tidy amount of musical prodigiousness, and progressive rock was born.
Of course it wasn’t called that back in the day, and whilst the early movers and shakers may not have sounded anything like each other, the one thing that linked the likes of Yes, Genesis, King Crimson, Jethro Tull, ELP and Pink Floyd was a fearlessness in the recording studio that matched the grandiosity of their musical ideas.
