BIRMINGHAM – They had a radio hit titled "Happy Jack" and they smashed their instruments.

That's all most young rock fans in Alabama knew about The Who when the band made its first appearance in Birmingham, 15 years and four months ago at a "Shower of Stars" show staged by WVOK, the city's top pop station. The Mod heroes had drawn acclaim at the Monterey Pop Festival five weeks earlier, but during the "Summer of Love" they were still touring across the United States as an opening act for Herman's Hermits, a mop-haired group that sang hits like "I'm Henry VIII, I Am."

The Who weren't even second on the bill at the July 29, 1967, show at the old Boutwell Auditorium. They were third behind the Hermits and Lou "Rhapsody in the Rain" Christie, on a bill that also featured Sam the Sham and the Pharaohs, Billy Joe Royal, and the local Rockin' Rebellions.

The Who played "I Can't Explain," "Happy Jack," "Boris the Spider," "Barbara Ann" and "Pictures of Lily" for several thousand clean-cut young teen-agers and pre-teens that Saturday afternoon. Peter Townshend, young, bony and scowling in his Union Jack coat, chopped out raw guitar chords with a windmill stroke no one had ever seen. Roger Daltrey was a blond, alto-voiced dandy. John Entwistle steady and sideburned. Keith Moon flailed his drums, the most energetic, wildest drummer anyone had ever watched. They all looked every bit as young as their 22 years.

Then they played "My Generation." When they stalked away four minutes later they left a debris of guitar fragments, amplifiers, cymbals and snare drums, a dull feedback hum and a film of thin gray smoke hanging three feet in the air.

Did you see that? the kids buzzed. They were still stirring in their seats when Lou Christie came on. Lou didn't seem to matter much at that point, and neither did Herman's Hermits a half hour afterward. Christie was only a tease – Frankie Valli in tight pants. Peter Noone was a wimp.

But The Who – The Who delivered, even if it was a 20-minute caricature of their own show. That was all the time WVOK allowed them.

FIFTEEN YEARS and four months later they closed the circle where they began, trotting onstage at the Birmingham-Jefferson County Civic Center Coliseum to open Tuesday night's sold-out concert with "My Generation" and "Can't Explain."

The new arena is only a few blocks from Boutwell, but The Who themselves are light-years beyond the early success of the first tour. Every other act from that "Shower of Stars" is barely a golden-oldies memory now. The Who, meanwhile, were drawing more than their generation on a rain-soaked evening – mainly high schoolers and young adults who were toddlers or had just started grade school in 1967, but a heavy sprinkling of longtime fans in their 30s as well.

Other sorts of their goodchildren collected in the cavernous, smoke-filled basketball palace. A teen-ager sauntered down the middle floor aisle in an oversized Army parka which bore "Who" written in white in a circle on the back – he was a twin to the youth on the cover of their "Quadrophenia" LP. One college undergraduate draped himself in a Union Jack poncho. Other fans sported everything from Sex Pistols punk buttons to 120d alligators.

THE STARS WERE in exuberant form for the second date on the second stretch of their farewell tour. (They played in Orlando, Fla., last Saturday following a break home in England.) Townshend, dressed lightly in checked brown trousers and a sleeveless white shirt, jigged around his side of the stage, winding up his windmill strokes during the opening songs, playing to the crowd. Daltrey, a matinee idol in jeans, sleeveless shirt and brown leather jacket, planted himself front and center, singing clearly, arcing his microphone seven feet out on its cord and snapping it back for perfect catches. Entwistle, the grayest-haired of the four, stayed unmoved at stage left in boots, dark trousers and a striped coat and shirt. Kenney Jones, the late Keith Moon's replacement, played hard and steady in a black warmup suit.

As thousands continued to hoot "Who! Who!", the band turned from early hits to selections from their current LP "It's Hard" – "Dangerous," the title track and "Eminence Front," all sounding more vigorous live than they do on vinyl.

WITH A SLIGHT pause and no introduction, Townshend strummed the opening to "Behind Blue Eyes." Daltrey stood at the edge of the stage in a pool of red light, holding back a wave of cheers with his soft, wistful vocals. The cheers erupted when Townshend tore into the song's guitar break.

The cheers continued at the familiar first notes of "Baba O'Reilly," another of their famous anthems and a high point of the concert. Townshend clenched a fist, stabbing it into the air in time with Entwistle's bass line. Clusters of small colored spotlights closed around Daltrey as he played out the song's harmonica solo.

A mixture of the new and the old followed – "I Can See For Miles," "Drowned" from "Quadrophenia," "Tattoo" from the 1967 album "The Who Sell Out," "Cry If You Want" (the only return to the new album) and "Who Are You."

Townshend and Daltrey, whose well-recorded offstage fusses have continued on this tour, shared a microphone on "Drowned," which also featured a long, sharp solo by Townshend. "Tattoo" came over as a Mod-era curiosity, while Townshend ripped out sizzling power chords through "Cry." Daltrey jogged in place during "Who Are You." They drew the first standing ovation at the close of a less-than-unrestrained performance of "Pinball Wizard" and "See Me, Feel Me." The stage and part of the arena were bathed in the hard white Hollywood-Bowl light of powerful rotating quad spots at the stage corners and a flashing panel behind the drums.

Townshend nudged his mike stand as he skittered through a hard-edged, windmilled version of "5:15." The stand wobbled – was this the awaited start of some impromptu violence? But no, Townshend kept on playing.

Daltrey grasped his mike stand as he wrenched out crescendo notes in "Love Reign O'er Me," then flung the stand back toward the amplifiers and dropped to his knees for the song's closing cry. He shared a microphone with Townshend again on the first chorus of "Long Live Rock," then crossed the stage for a duet with Entwistle.

THE STAGE LIGHTS darkened, and the audience cheered when the soaring, pulsing synthesizer of "Won't Get Fooled Again" filled the arena.

Townshend unloosened all of his moves and guitar chops as the anthem coursed along. Daltrey marched in place at the stage edge. As Jones pounded the song's break to a close, Daltrey poised himself for its famous primal scream, standing at the edge, grasping his microphone with both hands above his head. The scream instead was almost buried in the boom of the show's single pyrotechnic charge.

The brightest lights blazed on as another standing ovation formed. Midway back in the floor seats, an entire row of fans held up flash cards spelling out a message: "Smash It, Pete."

THEY ENCORED with a long instrumental from "Tommy", and "Squeeze Box," then the usually silent Entwistle took the lead vocals on the old Beatles arrangement of "Twist and Shout." The Who were finishing the show where they began almost 20 years ago – with a teen-age dance hall standard.

As Jones and Entwistle drove into the song's final flourishing chords, Townshend raised his Telecaster above his head. Would he do it? No one among the crowd of 18,000 wasn't wondering.

After two seconds of suspense, he thrust the butt of the guitar onto the stage for a single blow, enough to stir an echo of the feedback that was his trademark for so long.

He quickly grinned, unplugged the Telecaster, and handed it to one of the stage crew. He'd given everyone the last thing they wanted – just enough, in his own way.