After John Mayer was diagnosed with a granuloma, or throat inflammation, just above his vocal cord last month, the singer has undergone surgery to correct the problem.

The seven-time Grammy winner is now on complete vocal rest for a month or more. Last month he was forced to cancel performances with Tony Bennett in Los Angeles and at the iHeartRadio Music Festival in Las Vegas.

“It’s been a very long process in waiting to see if time was an alternative to surgery,” Mayer wrote on his Tumblr, “but even given two weeks voice rest (along with many other approaches), there was no change for the better.”

Mayer continues, “I should be frustrated but I can’t seem to stop thinking about beautiful things… I have this beautiful, meaningful record waiting for me when I can sing it.”

His upcoming fifth studio album, "Born and Raised," which was previously set to release this fall, has been postponed to release some time next year.