John Mayer

In frat houses everywhere, an acoustic cover of "Your Body Is a Wonderland" closes the deal with a Jessica Simpson look-alike 90 percent of the time. In Hollywood, John Mayer simply walks into the Ivy. The 32-year-old musician has long been recognized as the alt-bro Stevie Ray Vaughan, thanks to serious chops and a tubby guitar style he once likened to Sting's effusive baritone. He has also immortalized the quarterlife crisis, celebrity Twitter account, and melodic relationship ballad. Thanks to "Who Says?" Mayer's first single off his latest album, Battle Studies, here's another landmark: The wake-and-bake trip to Japan.