The Who bring Pete Townshend’s Quadrophenia to the CoreStates Center on Sunday, performing the brilliant but often-overlooked rock opera in its entirety in what is likely a test run for Broadway.

Before debuting it in London’s Hyde Park in June, the English classic rockers had never done the complete 1973 album live.

Since then, though, they have brought it to New York’s Madison Square Garden for five shows, followed by a U.S. tour that was expected to be one of the fall’s hot tickets but has struggled to sell out arenas. (A second scheduled Philadelphia show, on Monday, was canceled.)

Quadrophenia tells of a troubled British Mod named Jimmy whose “quadrophenic” personality Townshend conceived as reflecting the four faces of The Who. The current band includes still-powerful-voiced Roger Daltrey, 52, bassist John Entwistle, 52, and Townshend, 51, who mostly plays acoustic guitar behind sound shields to protect his damaged ears, plus drummer Zak Starkey in place of the late Keith Moon. The supporting cast includes Townshend’s guitarist brother Simon and hammy rockers Billy Idol and Gary Glitter.

The Quadrophenia tour, a likely test run for a Broadway-bound version of the rock opera, has been accompanied by plenty of Who-related releases.

There’s a new collection of Entwistle solo material called Thunderfingers (Rhino). The Rolling Stones Rock & Roll Circus (out on CD and video on Abkco) includes The Who’s performance of “A Quick One While He’s Away” that so impressed Mick Jagger he supposedly prevented the 1968 filmed-for-British-TV extravaganza from being televised because The Who had so outclassed his own band.

The Who at their turbulent, ferociously rocking best are showcased on Live at the Isle of Wight Festival 1970 (Columbia/Legacy). The two CD Tommy-era set takes its place alongside Live At Leeds as a testament to the band’s in-concert greatness, and includes an out-of-the-blue comment by Daltrey on Philadelphians’ peculiar way of pronouncing the word water.

And then there’s Quadrophenia itself. In the Townshend oeuvre, it’s been overshadowed by Tommy, but Who cognoscenti have always known Quadrophenia is the richer, more rewarding work. Twenty-three years after its release, it’s as stunning as ever, and its eloquent examination of male adolescence easily outdistances the self-absorbed angstmongers of the ’90s.

At Hyde Park in June, Quadrophenia felt like a dress rehearsal without the kinks worked out. But reports from the indoor U.S. dates have been uniformly positive, and the band has added an encore set of hits that should leave Who-aholics with everything they could have hoped for.

The Who, with Ocean Colour Scene, at the CoreStates Center, Broad Street and Pattison Avenue, at 8 p.m. Sunday. Tickets: $37.50 to $50. Phone: 215-336-3600.

The Who — (from left) Pete Townshend, Roger Daltrey and John Entwistle — play the CoreStates Spectrum Sunday.