Hendrix acolytes know the story well: the innovative guitarist met up with jazz legend and admirer Miles Davis with the intent to make an album together. What they didn’t know until today was that the two were hoping to get a ringer to join them on bass: Paul McCartney.

Recently, a telegram that Hendrix and Davis sent to Apple Records in 1969 has surfaced indicating that the two wanted to bring in McCartney to play on an album they were attempting to record with jazz drum maestro Tony Williams. A response said that McCartney was unavailable at the time and for the two to try again in two weeks. At the time, McCartney was trying to avoid public exposure after a radio station first reported the infamous rumor that McCartney had died in a car crash and had been replaced with a lookalike.

The telegram has been common knowledge for years, and the physical copy has been kept in the Hard Rock Cafe memorabilia archives since 1995, but it has started to generate more interest with the release of People, Hell and Angels, alleged to be the last collection of Jimi Hendrix songs left in the guitarist’s considerable vault of unreleased material.

As with a lot of things that involve the tragically short life of Jimi Hendrix, the possible collaboration between himself, Davis and McCartney is something that will leave fans wondering what could have been.