Pete Townshend (left) and Roger Daltrey covered all bases at the Garden on Monday.

The Who’s “Hope I die before I get old” line from “My Generation” has been quoted so often in irony — especially now that both surviving members have cracked age 70 — that guitarist Pete Townshend offered a frisky addendum on Monday at the TD Garden. After playing “The Seeker,” the first in a string of rarer early singles on “The Who Hits 50!” tour, Townshend claimed the final lyric was “I won’t get to get what I’m after, until I truly die.”

Indeed, Townshend and lead singer Roger Daltrey are still kicking, but the vital life of the Who as a band remains more questionable. Townshend has indicated this will be the group’s last tour, though the Who first embarked on a “farewell tour” in 1982. Some gave up on the Who with drummer Keith Moon’s death in 1978; others drew the line after bassist John Entwistle died in 2002. And the Who – doubled to eight musicians, including three keyboardists – didn’t help its case on Monday by frequently flashing photos and videos of the original foursome as a reminder of those potent blokes.

But rock legends die hard, and what now constitutes the Who put on a hell of a retrospective at the TD Garden, including choice four-song chunks of Tommy, Who’s Next and Quadrophenia. The show had been rescheduled from October due to Daltrey’s bout with viral meningitis, which wasn’t as juicy  in a rock ‘n’ roll way as reckless partier Moon forcing postponement of a 1976 show at the old Boston Garden when he collapsed at his kit after two songs.  Before the Who hit the stage Monday, a message flashed on the backdrop, warning smokers not to threaten the show because of Daltrey’s allergy, but that never became an issue. Given his voice problems (like Adele, fixed through surgery by Boston’s Dr. Steven Zeitels a few years back) and Monday’s news that AC/DC screamer Brian Johnson has been told to quit touring or lose his hearing, it was a joy to hear Daltrey in fairly solid voice, hitting the screech in “Won’t Get Fooled Again” for maybe one last time alongside Townshend.

Townshend was engaged, if sporatically, whipping off some windmill chords and taking a hearty lead vocal on his acoustic changeup “I’m One.” However, despite the glut of keyboardists, the real reason the Who clicked for most of its two-hour set was Moon disciple and Ringo Starr’s son Zak Starkey, the Who’s drummer for the last 20 years. His meaty, big and bouncy fills carried highlights from “I Can See for Miles” (iced by six-part harmonies) to “The Real Me” (thrillingly both taut and messy around Pino Palladino’s bass riffs) to “Bargain,” where Daltrey let the packed house chime the high refrain of “The best I ever had!” before the singer handled its last chorus.

There were flatter moments, including “Pictures of Lily” (perhaps too many hands on that pop song about masturbation) and Quadrophenia overture “The Rock,” mired in keyboards despite snappy guitar tradeoffs by Townshend and his brother Simon (who also balanced the funky lurch of “Eminence Front,” heard of late in Cadillac commercials). But to hear, see and feel Daltrey’s emotive “Love, Reign O’er Me” and a Tommy suite where he clapped tambourines and swung his mic like a lasso before the inevitable “Pinball Wizard” still brought goosebumps. Of course this wasn’t the Who of old, but the old Who delivered a dream mix of classic songs.