Mayer 'defends pro-marijuana single'

John Mayer has defended his decision to sing about smoking marijuana on his new single.

'Who Says' is the first track to be taken from the singer's new album Battle Studies and begins with the line, "Who says I can't get stoned?"

Mayer, who claimed in April that he had quit smoking the drug, said that he hopes his controversial lyrics will spark debate among listeners.

He told Pop Eater: "It's not a dirty word. It's not a curse word. It's a presentation of an idea that makes people think a little harder about what they're listening to, which I don't think is the worst thing in the world."