Keith Richards doesn't think Sir Mick Jagger's solo material is any good.

The 71-year-old rocker is always disappointed by his Rolling Stones bandmate's work away from the group and thinks he should just stick with being their frontman.

He said: ''I've got to say, when Mick goes out on his own, solo, I'm always expecting something and he just does not deliver by himself.

''Maybe this is one of the things that gets right up his snoot.

''Listen Mick, you're the greatest in the world, as long as you've got the Rolling Stones behind you. I think that rankles him.

''But it's just something I accept about the man. It's a point of jocularity among the band.''

And Keith is always amused by Mick's muted responses to his own solo work.

He told GQ magazine: ''Whatever he says I will then translate it to know what he really means. He'll go, 'Mmm, not bad.' He'll play it like that.''

Speaking about Mick's response to one of his previous solo tracks, 'You Don't Move Me' - which was about Keith's relationship with the singer - he added: ''Mick's got this incredible ability to blank it out. I never got any more feedback. Like it didn't exist...

''If he gives me a blank silence, I'll know he's heard [the new record].''