Welcoming us to "the first UK show of this long, long tour we're doing", guitarist Pete Townshend veered off into reminiscence about the Who's recent appearance in Abu Dhabi to coincide with the F1 Grand Prix there. "It was pretty cool," he informed. "Well, it was hot. But there's a better class of thug in Glasgow." This was the Who the crowd wanted, said the cheers for that last remark. Not the globe-bestriding multi-millionaire rock stars, but the skinny-hipped, lank-haired youth earthquake of their earliest vintage.

That Who is gone now but for this tour, Townshend, singer Roger Daltrey and a six-piece group, including Townshend's brother Simon and Ringo Starr's son Zak Starkey on drums, will do a great impression. Titled The Who Hits 50!, this extended jaunt will both celebrate the band's surviving members reaching five full decades together and say goodbye to the group following Daltrey and Townshend's decision to bring it to a close.

This first show before 12,000 all-seated fans was a curious beast, tentative yet emphatic all at once. Over two and a half hours, those who packed the hall would have surely heard everything they came for from that extensive catalogue – except there was no "My Generation", its removal perhaps a concession to the irony of its lyrical content being performed by a 70-year-old and another who will reach that milestone before this tour ends.

Yet there was plenty to remind of their earliest days as the set began, including sprightly run-throughs of "I Can't Explain", "Substitute" and "The Kids Are Alright". From there the show skipped through eras, and

it was the signature tracks that the group have been playing for decades that sounded most resolute and noisily pristine: a spine-tingling "Behind Blue Eyes"; the gripping, rocky epics "Who Are You" and "The Seeker"; the frazzled energy of "Pinball Wizard's" giving way to the staunch "See Me, Feel Me"; "Baba O'Riley" whipping the audience up to join in at full blast with its "teenage wasteland" refrain.

Yet there was also the sense that things were being tried out in advance of the long road ahead, with quite a few unexpected choices and a couple of songs that appeared to need tweaking ("Squeeze Box" required more banjo, for example). Rock mini-opera "A Quick One,

It was the signature tracks that sounded most resolute and pristine

While He's Away" excited enthusiasts, as did the early Eighties vintage "Eminence Front", which provided a good case that Townshend's bluesy bark is a more suitable instrument at this stage of their lives than Daltrey's still-incisive holler. Witness the pair vocally sparring during "Cry If You Want", Townshend's barked "you know the fuckers always lie!" upstaging Daltrey's breathless rap.

Amid it all, a mini Quadrophenia suite saw their late band members shown onscreen, John Entwistle's mesmerising bassline bossing the mighty "5:15" and Keith Moon's madcap laughing spoken-word part on "Bellboy" proving very welcome. The show rang to a close with a breathtaking "Won't Get Fooled Again", unnecessary encore of "Naked Eye" notwithstanding, and few would have complained at witnessing a mostly sure-footed first step on what the band call their "long goodbye".