John Mayer has publicly praised his ex-girlfriend Taylor Swift for leading a boycott of streaming service Spotify after taking issue with having her music given away for free.

The Shake It Off hitmaker removed all of her tracks from the site without prior notice in November (14), days after the release of her new album 1989, as part of a protest about the value of artists' work.

She was inundated with messages of support from fellow musicians and now Mayer has joined those in applauding her efforts.

During an interview with U.S. newsman Ronan Farrow, Mayer admitted her push against Spotify is "really cool", adding, "Artists need the person with the loudest voice to speak for them.

"You can go to the Met Ball (fashion gala). That's great. That's a great way to use your voice is to go, 'I'm wearing Valentino.' Or you can use your voice to give things."

Mayer also urged fans to stop dwelling on the subject of his 2013 song Paper Doll, which has long been rumoured to be about Swift, because he has more to offer than that one track.

The singer/songwriter, who is now reportedly dating Swift's nemesis Katy Perry, says, "The song never got listened to as a song. It became a news story because of the lyrics. I'm not in the business of telling people what the song's about.

"Now I can just go, 'Look, I can say the name Taylor Swift.' She's an artist. I'm an artist. Everybody stop, nobody's got cancer. We're rich people who get to live out our dreams. Let's just stop it. I'm a musician who's bigger than one song or one record."