“David Gilmour had been playing the riff. I said, ‘And then what happens?’ And he said, ‘No, that’s it.’ I said, ’Do you mind if I see what happens next?’” Roger Waters reflects on writing Pink Floyd’s Wish You Were Here – and the meaning behind it

David Gilmour (L) and Roger Waters (R) perform at a benefit evening for The Hoping Foundation on July 10, 2010 in London, England.

Pink Floyd's ninth studio Wish You Were Here will celebrate its 50th anniversary next year. The album, which spawned the iconic title track, features a memorable intro played on a 12-string guitar, which Roger Waters has revealed was the catalyst that inspired the rest of the song and set a melancholic tone for the rest of the album.

“It's one of those strange songs that came to me very easily, because David Gilmour had been playing the riff, and I've been listening to it and going, ‘What's that?’ And he played it. I said, ‘Play that again,’” he says in an interview with AXS TV.