John Mayer is the crooner whose mouth is more famous than his music, but a closer look at the 35-year-old reveals there might be a bit more going on. Yes, he's still dating celebrities (current flame Katy Perry is rumored to be tagging along on this tour), but the guy quit Twitter, was literally silenced by the surgical removal of throat granulomas, and even moved out of L.A. to rehab in Bozeman, Mont. (pop. 37,000), where his inability to hit high notes spawned a pair of subdued albums showcasing stronger songwriting and newfound humility. A respected blues guitarist who probably has Eric Clapton and Buddy Guy on speed dial, Mayer still has a hungry following (he hasn't toured in two years) who will wilt at the sight and sound of their hero. American Idol winner Phillip Phillips opens the show at 7:30 p.m. Saturday at the MidFlorida Credit Union Amphitheatre, 4802 U.S. 301 N, Tampa. $36-$89.70. (813) 740-2446.