If Jason Mraz's "I'm Yours" isn't stuck in your head at least three times a week, you're either a pop-culture-shunning dynamo or you've checked out altogether because the rest of the population can't drive three miles without hearing the slack-key-inspired tune on the radio — 17 times a day.

The San Diego-based Mraz, or Mr. A to Z to his fans, performs tonight at the Waikiki Shell to a nearly sold-out crowd, though at press time, tickets were still available.

When Mraz takes the stage tonight, it will be his second concert in the Islands, but it will be his first time performing his mega-hit for a local audience. And if the fact that the concert had to be moved from the Blaisdell Concert Hall to the Shell to accommodate the high demand for tickets is any indication, it's going to be one huge happy sing-along.

Mraz burst onto the pop music scene in 2002 with his debut album, "Waiting For My Rocket to Come" and has garnered a loyal fan base among indie popsters, as well a reputation for putting on one heck of a live show.

"I'm Yours" was a viral Internet hit before it was released for purchase on music download sites in February, thanks in part to Mraz's support of allowing fans to record live shows and disseminate the recordings.

Mraz's third album, "We Sing, We Dance, We Steal Things," is scheduled to drop May 18.