Progressive rock is a loose label covering bands who began to explore and extend the musical boundaries beyond the standard three-minute pop song. In tandem with longer songs came a penchent for far more complex musical and lyrical structures, the former using classical influences to involve long and technically complex musical forms, as frames for the latter, abandoning the 'boy meets girl' template in favour of sword-and-sorcery, poetry. and literature. The first 'progreessive rock' album was King Crimson's 'In The Court Of The Crimson King'. Lyricist Pete Sinfield and bassist Greg Lake brought their respective talents to the prog. trio Emerson Lake And Palmer who are founding members of the Progressive School of rock music. Add on early Genesis, Yes, Jethro Tull, and Dutch band Focus, and you have the genus of the progressive era, which lasted until it was rudely shifted aside by the revolt against the style that was punk rock. Progressive rock continues to flourish, even though early contenders like Genesis and Yes found pop sensibilities, and pop chart success - even Pete Sinfield wrote lyrics for Eurovision winners Bucks Fizz! Laughed at and lauded in equal measure, progressive rock is a main ingredient of early 1970's rock, and an influence - through revolt - on the pop and dance music of today.