A global search is on for one of the most iconic instruments in music history – ex-Beatle Paul McCartney’s original bass. The Lost Bass Project has asked for information on the whereabouts of “the most important bass in history,” the BBC reported.

McCartney bought the instrument in Hamburg in 1961 and played it on the songs “Love Me Do” and “She Loves You”, but it was lost eight years later after the filming of “Get Back”.

Project manager Nick Wass from the German manufacturer Höfner told the BBC that McCartney asked him about the whereabouts of the instrument – that’s how the search started. He worked closely with the 81-year-old and wrote a book about the missing 500/1, a model of Höfner’s first electric bass. “It’s unclear where it was stowed, who might have been there,” Wass said. “Most people will remember. It’s the bass that made the Beatles great.”