Justice. The band that everyone came to see, headlining a festival day whose electro-heavy agenda they anchored, Justice ruled the day. Captaining two LED-lighted sampling stations, bracketed on either side by amplifier rigs, the duo looked as if they were inside an enormous boombox. A designer boombox at that, the white-scripted Marshall logos fronting each amp aligned to mirror the repetitive designer print of fellow Francais Louis Vuitton. In step with their computerized compositions, the duo dressed in black leather, acknowledging the audience with mechanical upraised arm salutes, the suggestive hip-sway equivalent for robo rock gods.

The set exploded to a start with as blindingly brilliant a light display as a sound: Gold lamps swallowed the ambient starlight and even outshone San Francisco's fog reflected glow, burning day-long festival-goers' faces one shade darker; white strobe lights flashed and glitched, stop-time-animating the grinding and bobbing crowd, or slow glittering to replace the stars they'd supplanted.

Glowing from the center of the stage, the emblem of the band's first album, " " prophetically anticipated by milliseconds the band's transitions, coloring from blue to white, from white to black. The crowd followed soon after, as tens of thousands of islanders surged and swelled like spastic tidal currents.

The set opened with the known and adored "Genesis." From there Justice surgically sampled and spliced sounds from the album. "D.A.N.C.E." appeared first over a murky minor industrial beat, gradually brightening until it supernova-screamed into the familiar song, newly arranged with tantric stretches and trance stasis. With a decibel level pushed past 11 on each of 18 amps, Justice blasted their beat into the bay, with a bass more ground-shaking that '89 and a sonic high to wake far-off dogs and festival dancers alike.

Antibalas. Eleven members strong, afrobeat outfit Antibalas takes its name from the Spanish word for "bulletproof." After a decade of music making, touring through 100 concert performances per year, the band's indefatigable energy and innovation prove the name fitting.

Lead singer Amayo, the face of the band, embodies Antibalas' funky flair sound with a persona that leads one to wonder who his groupies are. Dressed in a pink and white suit, with flared pant-legs and pattern coordination evocative of '70s disco and round-ended collar wings inspired perhaps by Jar-Jar Binks, Amayo danced and sang as if possessed. He even spoke in tongues and had the audience do the same, a twenty-thousand loud West-African call-and-response.

Indebted to the rhythms of Cuba, Africa and the melodic grooves of jazz, funk and dub, the group alloys this mix with a stage presence evocative of the hammer kneed, grittle hot shouts and counts of James Brown. "One-Two-Three-Hit Me!" cues the brassy bravado of the band as Amayo shimmies and slides. As a jam band with 20 minute long vamps torn apart by trumpet growl and landslide-low sax solos, the band offered a playlist varied enough to wake into movement every muscle.

The band lapsed into politics for one song, a funk-punk fusion number, the guitarist yells, "Condoleeza-Indictment, Bush-Indictment, O'Reilly-Indictment." His voice raised, impassioned in anger, and he advanced the bands sonic palette with a harsh, fierce sound. Able to craft a new song style around this tone, the group appropriately paired punk and politics; any other arrangement would have seemed incongruous, what with content so weighted that it sounds like yelling even when whispered. Set in the liberal, blue-state Bay, however, Antibalas couldn't have played a festival more receptive to that vision.