Songfacts®:

• This song was written as a tribute to Bruce Berry, a Neil Young roadie who died of a heroin overdose. Berry was the second noteworthy person in Young's life to die of a heroin overdose, the first being Danny Whitten, Crazy Horse's original guitar player. The song is unusually detailed for a requiem. It takes a series of candid snapshots from Berry's life, describing how he drove the van, slept late, and clowned around with Young's guitar after gigs.
• Neil Young's Rolling Stone interview concerning this song and album is recorded in Neil Young: Long May You Run: The Illustrated History: "Tonight's the Night is like an OD letter. The whole thing is about life, dope, and death. When we played that music we were all thinking of Danny Whitten and Bruce Berry, two close members of our unit lost to junk overdoses. We played Bruce and Danny on their way all through the night."
  
  Speaking of "Tonight's the Night," Young declares what might as well be his M.O. for all of his art: "All of these things happen to people, so I figured it happened to me so I'll write about this, and I'll just write from my heart, and if other people have this happen to them they'll relate to this."
• Neil and Crazy Horse recorded this song without playing it back until after they finished it, which added to the raw sound that the song would be recognized for. Musicians on this track were:
  
  Young - piano
  Billy Talbot - bass
  Ralph Molina - drums
  Nils Lofgren - guitar
  Ben Keith - steel guitar
• This song opens the album, and the closing track is "Tonight's the Night - Part II," a more spare version of the song. Using two different versions of a song as the opener and closer is a trick Neil used several times in his career, including on his album Rust Never Sleeps ("My My, Hey Hey (Out Of The Blue), "Hey Hey, My My (Into The Black)") and Freedom ("Rockin' In The Free World").
• Young got the idea to start and end the album with "Tonight's the Night" from a two-day benefit concert he did at the Topanga Corral, where he opened and closed the shows with the song "Walk On." He liked the idea of one song at the beginning and the end, but changed the tune itself.
  
  Young says in Shakey, "There were a few 'tonight's the night' songs in the show, but it wasn't the 'Tonight's The Night' vibe - it was the 'Walk On' vibe. We'd do 'Walk On' when we walked on, then we'd do it when we walked off. So that concept of doing the same song at the beginning and the end happened with 'Walk On' - then we dropped 'Walk On' and put in 'Tonight's The Night.'"
• Touring Tonight's The Night in London, Young frequently made a spectacle of himself with his drunkenness and appearance so unsavory that it's been likened to psycho-cult leader Charles Manson.
  
  One night in London, Young went on a revealing ramble about how Bruce Berry "lost" one of the band's guitars, forcing Young to fire him. Berry came back to Young a couple years later looking for work.
  
  "We looked at him and I said, 'I'm sorry, man, can't do it. I mean, ya lost David's guitar, y'know," Young said. "You don't know what happened to the guitar, it's gone. Ya lost his guitar, man, I mean, that's his ax. That was it. Ya lost it. That's your job and you lost it... You took that guitar and you put it in your arm, Bruce."
  
  During another show on the tour, Young said he was going to raise Berry from the dead "right here at the Hippodrome," before slamming wildly on piano and yelling repeatedly, "You took that guitar and put in your arm."