It's too bad concert photographers are required to leave after the first few songs, because one particular shot at Saturday night's Weezer show at the State Fair grandstand show would have said it all: that of singer Rivers Cuomo wearing cartoony Superman underwear over his khaki pants.

OK, so maybe a little more needs to be said on the matter.

Fourteen songs into Saturday's childishly entertaining but musically fulfilling fair concert, a fan threw the adult-sized Man of Steel Underoos onstage. Lo and behold, the once-insular and still-nerdy frontman of the hit-making '90s alt-rock band proceeded to try on the Super skivvies -- hopefully a prize won at the Midway and not a pair put on midday. That they happen to arrive just as Cuomo got around to singing, "I come undone," was too good a coincidence. That they stayed on for several more songs was too weird.

Playing its second local outdoor show in as many years (after last year's Basilica Block Party), Weezer was more madcap and ridiculous than ever in a dumb summer-fun way. But its breezy set was also seriously rousing and satisfying in the kind of high-energy, loud-guitar-baked arena-rock way that was sorely missing in this summer's concert season of pop princesses and cooler-but-drabber indie-rock bands.

Weezer's set only lasted 75 minutes -- about the length of a single Steely Dan jam a few nights earlier at the grandstand. In that time, though, the band wham-bammed through 16 of its best-known songs, each executed as tightly as Cuomo's extra undergarment and all buoyed by the general-admission crowd's gleeful reception. The 8,765 fans never had a chance to rest their vocal cords or stop bouncing to the music.

In addition to its own car-stereo-honed canon of hits -- "Say It Ain't So," "Hash Pipe," "Island in the Sun" and the irrepressible "El Scorcho" in the first half, "Undone (Sweater Song)," "Pork and Beans," "Beverly Hills" and "Buddy Holly" toward the end -- the band also dropped in two playfully picked cover songs that underlined its line-toeing approach between mass appeal and music geekery.

Early in the set came Foster the People's "Pumped Up Kicks," this summer's catchiest rock hit, which the more veteran Los Angeles pop-rockers played with a lazy indifference. Much more challenging and callously rocking, Radiohead's arty masterpiece "Paranoid Android" kicked off the encore with its roller-coaster ride of jagged time changes and jarring guitar bursts, all of which the band spotlessly pulled off. Not only would Radiohead fans have been impressed, those Steely Dan fans probably would've dug it too.

Much credit for the show's added oomph value goes to Weezer's lineup switcheroo that took shape last year and stuck, with omnipresent drummer Josh Freese (Guns N' Roses, A Perfect Circle, Nine Inch Nails) taking over for original timekeeper Patrick Wilson, who now plays guitar.

Not only is Freese a heavy hitter and Wilson an adept guitarist, but the new arrangement allows Cuomo to put down his guitar and jump around the stage more. He's no David Lee Roth, what with his thick glasses and button-down shirt. Cuomo has come a long way from his shoe-gazer years, though, and he's predictably funny when he does get to talking.

When the singer returned a woman's shoe from the stage and then got a bra thrown at him (probably a precursor to the underwear tossing), he cracked, "That's a fair trade." And during the opening build-up of "Undone," he improvised a great little nostalgic rap about the year the song made Weezer famous, 1994: "When we used to have to call our manager from a pay-phone," he sang, "And MTV used to play music."

Who needs MTV? Cuomo seems to be starring in his own wacky TV show nowadays, and it's worth viewing in reruns for years to come.

Local openers Motion City Soundtrack -- who toured with Weezer last year and are part of its upcoming concert cruise -- impressed a good chunk of the older alt-rock crowd but were especially cheered on by the equally numerous teenaged fans, who sang along to such poppy songs as "This Is For Real" and "The Future Freaks Me Out."

On this night, though, everybody had a little teenager in them.

See Weezer's set list at startribune.com/music

Chris Riemenschneider • 612-673-4658 Follow him on Twitter: @ChrisRstrib