Is anyone here a King Crimson fan?
King Crimson is an English group formed by, guitarist, Robert Fripp. They laid the foundations for progressive rock and continued to build upon the genre. They released their debut album, In the Court of the Crimson King, in 1969 and continued to released albums until 2003 and are now on hiatus.

I love the amount of improvisation they put into their songs. They have a large amount of improv during their live shows and in the studio.