The Who seemed achingly past its prime Tuesday night at Darien Lake Performing Arts Center.

The Rock and Roll Hall of Famers gave an uneven, though at times inspired performance. Despite occasional flashes of brilliance, especially during a boisterous, turn-back-the-clock encore of hits, the Who just wasn’t up to its legendary reputation.

The quality of the concert — which offered a heavy dose of “Quadrophenia,” Pete Townshend’s flawed rock opera — didn’t seem to matter to the giddy, reverential crowd.

The Who first retired nearly 15 years ago but has managed a variety of comebacks ever since. The band has perfected the art of exploiting itself as an icon oldies act to the classic-rock generation.

For the few non-worshiping unbelievers who hold the Who to its highest standards, this gig was a dismal jolt of reality. It was enough to make me go home and listen to “Live at Leeds” one more time as a reminder of what a great band sounds like.

Now we have to look in the mirror, boys, and see:

• Pete Townshend, partially deaf, with a bum wrist and balding head. Townshend’s guitar windmills have slowed; he can still turn on the juice, but only in short segments.

• Roger Daltrey, the sexy lead singer in tight jeans, can still twist a microphone like a lasso and shimmy and shake across the stage, but he has problems hitting high notes. Daltrey oozes charisma with his curly blondish hair and rippling muscles, but he showed signs of lethargy — as might be expected from a performer in his 53rd year.

• John Entwistle, stoic and robotic, plays the same role as always: off to the side, hunched over his bass, lost in a hypnotic musical daze.

The Who, when the spirit is willing, can still rock the house. Townshend’s blistering guitar, Daltrey’s searing vocals and Entwistle’s bass-slapping notes still transcend pop music and combine for majestic rock ’n’ roll.

Those moments, however, seemed to come and go in quick spurts at the concert. One reason is the absence of Keith Moon, who died long ago and on this tour is replaced by Zak Starkey, Ringo Starr’s son, on drums. Simon Townshend, Pete’s brother, does journeyman work on guitar.

Unfortunately, the Who continues to play “Quadrophenia.”

Townshend appears determined to convince the public that this confused tale of rockers and Mods in ’60s England is his masterwork, but it will never be confused with “Tommy.”

It seemed muddled and overbearing at times, with old and new film clips shown on a giant screen above the stage. Guest actors and singers on stage added to the congestion as Townshend seemed to direct a Broadway play combined with a rock concert.

Who fanatics may find the live version of “Quadrophenia” a near-religious experience, but the rest of us are still trying to figure it out.

But the encore truly displayed what rock ’n’ roll is all about. It was almost worth the wait of sitting through the rest of the show.