Two standout performances book-ended this writer's Saturday-night experience at Austin's South by Southwest music fest, beginning with Joss Stone [ tickets ]'s performance at the Town Lake Stage at Auditorium Shores, and ending with Papa Roach [ tickets ]'s frenetic performance on the outskirts of town.

Stone's dynamic, Southern-flavored soul-singing comes as a surprise, considering the almost-17-year-old U.K. girl delivering the goods. Her talent elicits several lengthy rounds of applause, and she's still innocent and naïve enough to truly appreciate the crowd's adulation. Unlike some peers who share her physical attributes, but not her talent, this blonde teenager truly deserves the attention.

Next stop: Piebald [ tickets ] at Emo's Annex. The Boston-based, emocore band's set includes material from its award-winning album "We Are the Only Friends We Have," which last year took the Boston Music Award for Local Album of the Year. Lead singer/guitarist Travis Shettel needs to eat something. Please; someone feed him.

Across the street, comedian David Cross finishes up his Bush-bashing routine. He caps his shenanigans by riffing on Lee Greenwood's "Proud to Be an American," lambasting the song for its heavy-handed jingoism, and rounding things out by talking to a booming-voiced, off-stage God, who assures the tongue-in-cheek Cross that America is the chosen country, and that the Christian God is the only true deity. We, the tightly packed crowd, eat it up.

The sounds of hip-hop emanate from The Vibe, where one M.C. from The Living Legends [ tickets ]--backed by a lone DJ--delivers several worthwhile raps.

Loud rock spills out from The Drink, as U.K. trio The Keytones finishes its set. The brief glimpse is all it takes to determine that the group--reminiscent of Nirvana and Silverchair--is one not to miss next time the chance arises.

London's Razorlight [ tickets ] kicks off a midnight set at the Hard Rock, and its shaggy-maned lead singer, who leads the group through a batch of Brit-pop-rock, evokes images of Mick Jagger-meets-J. Geils Band's Peter Wolf.

At 1 a.m., the lights drop at the Backroom--a club situated in a strip mall far outside the downtown area--and Papa Roach explodes onto the stage. The group runs through an incendiary, high-powered set that incites the crowd into a near frenzy.

Lead singer Coby Dick is a man possessed. He slams the microphone against his skull, then leaps off the stage and moshes his way through the up-front crowd during the very first song; his handlers keep his microphone cord free from obstacles and look on anxiously as they wait for him to return to the stage. He does, and the band subsequently spends much of its set tearing through new material that will turn up on an album due out this summer.

The group's set also includes "She Loves Me Not" from 2002's "Lovehatetragedy" and show-closing, fan-favorite "Last Resort."

The high-octane performance has little in common with Stone's soulful delivery earlier in the evening, but the most-evident similarity is also the most important: both turn in performances that those in attendance will likely be talking about well after this year's SXSW comes to a close.