Rolling stones rocker Keith Richards thinks Justin Bieber's music is "a load of crap".
The 71-year-old guitarist has admitted he's unimpressed with modern pop stars, describing Justin and Taylor Swift as little more than the "flavour of the month".
He explained: "Taylor is a pretty girl. I don't think about the competition. I mean they're the flavour of the month, aren't they?"
Keith said he found Justin to be "quite humble" when they met, but thinks his attitude is a reflection of his uninspiring music.
The Rolling Stones legend told GQ magazine: "Justin Bieber? Actually I met this guy and found him quite humble, as he should be.
"His music? I mean it's a load of crap isn't it?"
Earlier this month, Keith hit out at his Rolling Stones bandmate Mick Jagger, saying he's a "control freak".
Keith said: "He's such a snob. He can come off that way even to me and the rest of the band. He comes on the plane and doesn't say, 'Hey mate.'
"He's preoccupied with something really boring. He's a control freak. He likes to know everything that's going on. He lost himself a bit in the details."
However, Keith was also quick to praise his bandmate.
He added: "He's a hell of a frontman. I still love him dearly. Your friends don't have to be perfect."