Jack Johnson performs at the Coachella Music Festival in Indio, California April 25, 2008. [Agencies]

Mellow music king Jack Johnson gave summer a gentle sendoff Sunday night, turning a massive stage at UCLA's Intramural Field into a breezy beachfront shack. All that was missing was the sound of rolling waves and grains of sand, though some women kicked off shoes or sandals to dance slowly in the grass anyway.

The antithesis of rock star ego, the Hawaiian surfer-filmmaker-troubadour has home-grown a large following, filling arenas and amphitheaters with his mostly acoustic-based folk-pop and reggae lite style with a touch of jam-band noodling.

This outdoor gig fit the Labor Day weekend vibe: The crowd of 17,000 or so included coed couple college fans and families with young children, the latter thanks to Johnson's many kid-friendly tunes, especially his "Curious George" soundtrack hit "Upside Down."

The set also featured such favorites as the sly "Flake" and the silly-romantic "Bubble Toes," first in its original, sung-from-a-hammock acoustic form, then shifting into scratchy soul-funk. There were his usual teasing detours into snatches of oldies, like the Cars' "Just What I Needed," always crowd-pleasing.

Despite his general laid-back mode, Johnson's themes aren't all whimsical, as in the title song to this year's album "Sleep Through the Static," with such socio-political lines as "Who needs please when we've got guns?/Who needs peace when we've gone above/But beyond where we should have gone?" He might be a nice guy, but he's not vapid -- far from it.

So while the show lacked heat, playing out at a daydreamy pace, it's tough to dismiss Johnson completely. Although he never strays from that soothing comfort zone, he's a solid songwriter; he just needs more range. He also has a big heart as a champion for the environment, from promoting organizations to running the greenest tour possible. His audience is in tune with that as well, which is certainly more constructive than typical rock rabble-rousing without purpose.

The night's support bands included Oakland indie-pop outfit Rogue Wave, which is signed to Johnson's Brushfire label; group frontman Zach Rogue joined him for a number during the headlining set.