JOHN MAYER Continuum NMC/Sony With a reputation as a Dave Matthews clone and as the author of schlocky, guitar-driven ballads, crooner and guitar virtuoso John Mayer has grossly misled us. He would have, anyway, if we hadn't been paying attention to the singer's touring-only side project, the John Mayer Trio. Mayer, you see, has always insisted he's a soulful guitarist heavily influenced by jazz and the blues, despite his work on the massively popular, Grammy-winning pop songs "Your Body is a Wonderland" and "Daughters." His jazzbo tendencies have occasionally threatened to reveal themselves with an unconventional chord choice in one of his songs, but due in part to marketing decisions by his record label, he hasn't been able to fully express himself. Now, with a couple of Grammy awards under his belt and sales that make would make any record company a touch more indulgent, Mayer is in a comfortable place as a musician, and can pretty much do what he wants. And what he wants is to sing the blues. And the kid's got cred. With appearances on albums by legends such as Herbie Hancock, Buddy Guy and B.B. King, the 29-year-old Mayer has undeniably cemented his place in the pantheon of contemporary guitar heroes. On Continuum, his third major-label release, Mayer soaks his ballads with bluesy licks, and instead of singing to his virtual prom date, tackles more substantial and adult themes with his soft and smooth vocal delivery. On the opening track, "Waiting on the World to Change," Mayer channels his inner Marvin Gaye in both melody and demand for change, singing, "The world and those who lead it / We just feel like we don't have the means / To rise above and beat it." To his credit, Mayer released "Waiting on the World to Change" as Continuum's first single. It's a strong statement for an artist usually embraced by legions of love-starved teenage girls for his dreamy-eyed balladry. Continuum is a passionate album, and without a doubt the best of Mayer's career to this point. The guitar work is phenomenal, with Mayer filling every open space with gentle but tasty guitar licks. Mayer also pays homage to guitar god Jimi Hendrix with his cover of the poetic "Bold as Love." The song is a welcome addition, and Mayer, unsurprisingly, tackles Hendrix's riffs with comfort and ease, giving the song an appropriately reverent air. This isn't Mayer radically redefining another artist, as Hendrix himself did with Dylan. Instead, the album serves as a respectful nod to the giants who came before him. It's that kind of attitude that gives one high hopes for the future of Mayer's career.