A rare video has surfaced on YouTube of the late Frank Zappa jamming with Pink Floyd in 1969.
The jam session took place during a music festival in Amougies, Belgium in October 1969, just two months after Woodstock. Film of the performance would premiere the following year but was later banned - reportedly because Pink Floyd didn't like how they came off on screen.
Zappa is seen calmly smoking a cigarette onstage before joining Pink Floyd on a version of "Interstellar Overdrive". He doesn't play much, but Floyd drummer Nick Mason would later say "the little he did... was terribly correct".