John Mayer had a Christmas to remember when he learned he could sing again after a six-month silence following a second operation on his throat.

The singer/songwriter returned to the stage as a singer on 16 January (13) at a benefit concert in his adopted Montana - but he now admits he could have come back sooner because doctors gave him the all clear to hit the high notes again in mid-December (12).

Mayer reveals it took him a month to reassure himself that his vocal problems were a thing of the past.

He tells Rolling Stone magazine, "I had been given the clean bill of health... (but) I didn't really believe it. I actually had them go back another time to look again, and I kind of feel like I want to go back a third time, because I'm just not used to it going my way.

"You can't even call it a granuloma anymore. It's called a retinoid, which is where the granuloma was. It's gone. After being plagued by it for two years, you almost keep thinking it's like the end of Nightmare on Elm Street. There's always this moment that it's gonna come back, and I'm learning that that's my imagination."

And he admits the operation and his lengthy silence has changed his voice: "I don't have the projection. My laugh changed. The way I used to laugh is kind of like that 'I'm embarrassed' high-pitched laugh. I don't really laugh that way anymore. I've found new ways around everything - new ways to talk, new ways to laugh. Now I wonder if I can go right back to the shape of my voice that I had when I was singing once I can do what I want to do with it."