Short answers, pulled from the story.
John Lennon created Revolution 9 during recording sessions that began on the 30th of May 1968 at EMI Studios. The final stereo master was completed on the 25th of June 1968 after multiple overdubs and mixing sessions.
The track has varying durations depending on the release version with some editions lasting 8 minutes 13 seconds and others reaching 8 minutes 22 seconds. Later CD and digital releases moved a conversation segment to the beginning of the song which altered its total length compared to the original vinyl pressing.
Music critics Robert Christgau and John Piccarella called the piece an anti-masterpiece while Alan Walsh described it as noisy boring and meaningless. A 1971 poll conducted by WPLJ and Village Voice voted Revolution 9 the worst Beatles song despite Ian MacDonald noting its cultural significance.
Prosecutor Vincent Bugliosi asserted that Charles Manson believed many songs on the White Album contained references confirming his prediction of an impending apocalyptic race war scenario. Manson mentioned Revolution 9 more often than any other album tracks and interpreted the sounds as parallel to Chapter 9 of the Book of Revelation.
Kurt Hoffman Band Weeds performed the track in 1992 and Phish played it during their Halloween 1994 concert released as Live Phish Volume 13. Other groups including Def FX Little Fyodor Shazam Rogério Skylab Alarm Will Sound Neil Cowley Trio United Nations Marilyn Manson and White Zombie all recorded versions between 1987 and 2016.