Supergrass's Diamond Hoo Hah

Genre gatekeepers, place your right hand on your copy of Menswear's Nuisance and repeat: "I swear on the Gallagher brothers' eyebrows that I will never again label Supergrass a 'Britpop' act." Despite an ability to brilliantly filch from the English canon, the Oxford quartet had little in common with their fellow countrymen; Supergrass's sketch-humor tomfoolery and fast-and-loose sensibilities largely separated them from the chin-stroking Albarn/Anderson sect. They also took the genre's zest for commercial appeal to new heights, embracing the idea of charming not just the majority, but everybody.

On those first four LPs, that infectious exuberance and shameless populism never waned, rendering the band's intent to bring new energy to old forms splendidly explicit. But 2005's Road to Rouen, and now Diamond Hoo Ha, find Supergrass mired in a sort of stasis. We always knew the lads were limited to just three chords; with efforts that feel measured, contrived, and dawdling, they finally sound like it. The title "Return of Inspiration" alone seems to acknowledge Rouen's missteps, but then the song makes some of its own, filling space with bits of harp and brass. And there's the problem: Supergrass tracks aren't supposed to have space. "When I Needed You" and "Ghost of a Friend" feel just as stretched out and thin. Only "Rebel in You," with its sugar rush of keys and background vocals, betrays that trademark fondness for breakneck, giggly dalliances with the classics (Buzzcocks, Small Faces, Hawkwind, etc.).

Supergrass are more crucial than many care to acknowledge; their album In It for the Money shaped the post-Britpop scene to a greater extent than 1997's other landmark releases: Ladies and Gentleman We Are Floating in Space, Urban Hymns, and even OK Computer. But now they're increasingly guilty of the same all-reference-and-no-substance fluff as their younger post-Britpop rivals, no better than Razorlight or the Kooks or Kaiser Chiefs wanly pumping on your stereo.

Supergrass play Webster Hall (websterhall.com ) July 30