Justin makes crap music: Keith Richards

London: Rolling Stones rocker Keith Richards thinks Justin Bieber's music is "a load of crap".

The 71-year-old guitarist said he is unimpressed with modern pop stars, describing Justin and Taylor Swift as little more than the "flavour of the month", reported Contactmusic.

"Taylor is a pretty girl. I don't think about the competition. I mean they're the flavour of the month, aren't they?," he said.

Richards said he found Justin to be "quite humble" when they met, but thinks his attitude is a reflection of his uninspiring music.

"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?"