Hey, It's That Guy! / Hey, It's That Voice!: King Crimson borrowed members from or to a number of other prog bands with its various lineup changes, but John Wetton is probably the most prolific outside the band (he was also the lead singer for Asia and UK, just to name a couple.)
Fripp lent his guitar services to other groups on occasions, including:
Throw It In: Gordon Haskell's laughter at the end of "Indoor Games". Also, the spoken part of "Thela Hun Ginjeet" (see Spoken Word In Music in the Main tab).
What Could Have Been: Elton John auditioned for the band during the sessions for In The Wake of Poseidon. Others who auditioned include future Roxy Music singer Bryan Ferry and Yes vocalist Jon Anderson. The latter gives us a small taste of what could have happened had he been accepted into the band on the movement "Prince Rupert Awakes" from the song "Lizard", as Haskell had already left the band by the time that section was recorded and Anderson was brought in to record the vocal part.
During the Islands era, Fripp toyed with the idea of recording Crimson songs in different styles than originally conceived; e.g "The Court of the Crimson King" as a Chicago Blues number.