You may be surprised to learn that both Martin Scorsese and Chris Rock appear in "One Direction: This Is Us." They're not together, but they're seen around the same time in the pop music documentary as having attended the boy band's Madison Square Garden show last December. Each is apparently accompanying their daughter to the concert, but they also claim to be fans of the group themselves.
It's really not that uncommon for concert films to feature celebrity cameos. Famous people like music, too, and often they get backstage perks because of who they are. They then end up in the movie because, well, again because of who they are. Many One Direction fans may not recognize Scorsese on screen, but it will be neat for some fans' parents to see him there.
Below we've come up with a guide to celebrity cameos, most of them uncredited, in ten other concert films -- in the event you need an excuse to watch some classic music docs about bands you're not into.