Hunger, both literally and figuratively, can be a difficult thing to quantify.

But when it comes to hunger for success in the music world, the yearning to reach the masses is often easiest to spot in a live concert setting. The 2006 Reggae on the River festival, held last weekend before a crowd of 15,000 in Northern California, showed off two artists at opposite ends of the hunger spectrum, despite the fact that they've both been at it for more than a decade.

Sean Paul and [no longer Baby] Cham came into the festival as perhaps the two hottest stars in dancehall at the moment, but while the former acted like it and mostly went through the motions during his set, the latter poured himself into a sizzling performance.

Sean Paul is the most successful Jamaican artist alive, with his 2005 album The Trinity scoring multiplatinum sales and two scorching singles in "We Be Burnin'" and "Temperature." But although his hour-long set Friday night blazed through hit after hit, from "Gimme the Light" to "Shake That Thing," it clearly lacked gusto and dynamism. With his US tour with Mariah Carey kicking off tonight in Florida, Sean Paul's thoughts were elsewhere and it showed.

After just the second song of his set, the vocalist went to the back of the stage, leaving his hypeman to ask the crowd, "If you want some more Sean Paul, make some motherf***in' noise!" That sort of tease might work at the tail end of a set, but doing so repeatedly throughout the set, as Sean Paul did, reeks of conceit.

Although his "Ghetto Story" is the dancehall hit of 2006 and has already landed remixes featuring Akon and Alicia Keys, Cham's performance Friday night was anything but lethargic.

The Jamaica native blazed through a set that was full of both bravado and modest charm, and in a journalists' roundtable afterward, Cham displayed a keen perspective. Of the "Ghetto Story" remix featuring Keys, Cham said he was honored that the soul songstress would grace his song but wasn't worried about riding in the fast lane to stardom.

"Hopefully [the remix] will help me get to a higher level but that's not what it's about," he said. "You have to stay focused on the music. You don't want to cheat the music. I want to be happy that I made music my way."

Cham looked plenty happy on stage Friday, prancing and dancing around while rolling through tracks from his upcoming album, aptly titled Ghetto Story, which hits stores August 15. He even threw in a decidedly cheesy but endearing medley of "Lean On Me" and Bob Marley's "One Love," and the crowd ate it up.

But while the set was full of tracks that showed off Cham's ability to switch back and forth between the classic Jamaican "toasting" vocal style and that of a singer, bedlam ensued when the band started into the opening bassline of "Ghetto Story."

Over a plodding, ear-grabbing track written by dancehall super-producer and Cham mentor Dave Kelly, Cham darted into the narrative lyrics of growing up in poverty-ridden Kingston: "I remember those days when hell was my home/ when me an' mama bed was a big piece a foam." The song is ghetto storytelling at its a**-shaking finest.

So will Cham follow Sean Paul to superstardom? That remains to be seen. But it's pretty clear he'll be taking his own road to get there.

"Every day is a new beginning," Cham said after the show. "My only aim is to make good music."