Songfacts®:

• This wordless a cappella song is about the death of Christine Gail Hinton, who was Crosby's girlfriend, muse, and partner. She was killed in a car accident on September 30, 1969 while taking their cats to the vet. Crosby explained to Mojo Magazine January 2008 why he wrote about such a tragic subject: "I guess you can feel exposed but what else are you going to write about? If you are going to write and record material which moves people it needs to be pulled from real life. You don't really have a choice."
• Crosby explained the song's origin story in the liner notes of the 1991 CSN boxed set. "I don't know where that came from. It was a hallucination. I've always been drawn to strange vocal works. I overdubbed six tracks a cappella, with echo. Later I was left with a persistent feeling it was about Christine Hinton, by girlfriend who was killed. I was very much in love with her, and she went away very suddenly. I was not equipped to deal with the loss. This piece was a sudden, improvised, overwhelming requiem."
• Running just 1:19, "I'd Swear There Was Somebody Here" is the last track on David Crosby's first solo album, I'd Swear There Was Somebody Here. The song is made up entirely of his vocals.
  
  After releasing the Déjà Vu album in 1970, Crosby, Stills, Nash & Young set to work on solo albums. They mixed and matched in various configurations, but didn't release another album with all four members until American Dream in 1988.