The most sought-after unreleased song in the Pink Floyd catalog is an alternate version of the title track Wish You Were Here found on new versions of the 1975 album out today. Jazz violinist Stéphane Grappelli, who was recording at London's Abbey Road at the same time, joined the band in the studio, adding an impromptu, haunting mid-song solo. Of the entire ongoing campaign of refurbished Pink Floyd releases, that track is "perhaps the best piece we have, because no one has heard it before. We all thought it had been lost forever," says Pink Floyd drummer Nick Mason. "When I hear it, I'm astonished, really, that we didn't go, 'Of course, we must have that.'"
Now, thanks to the magic of youtube, you can hear it right now for free: