By Mark Simpson
North of England correspondent, BBC News
You know when rock stars are heading towards their sell-by date: fans start putting plaques on walls so that no-one forgets about them.
The Who were famous for trashing their instruments at their live shows
And that's what happened before The Who's concert in Leeds on Saturday night.
The unveiling ceremony wasn't very "rock and roll".
In fact, it was all extremely dignified, and apart from one stray F-word, terribly well mannered.
Roger Daltrey and Pete Townshend looked like two trendy english literature lecturers as they climbed the steps of Leeds University's students' union and pulled back the curtains on a blue Civic Trust plaque.
It was to mark 36 years since The Who's finest moment, the recording of the legendary Live at Leeds album. Q Magazine recently voted it the best live album of all-time.
Years rolled back
For almost four decades, fans have been demanding a repeat performance - and on Saturday night they got it.
For two hours and 20 minutes, The Who defied the statistic that made them the oldest rockers in town.
At 62, Roger Daltrey has no right to look and sound so sprightly. His trademark unbuttoned shirt revealed a chest and six-pack that wouldn't look out of place at the World Cup.
As for Pete Townshend, his fabulous flashing fingers certainly don't appear 61 years of age.
A blue plaque commemorates the band's original gig in Leeds in 1970
OK, so they needed a short break halfway through the concert, but who didn't?
By the end, as they belted out an unforgettable rendition of Won't Get Fooled Again, the crowd seemed more in need of a breather than the band.
One 60-something man was doing his best to look hip and cool as he sang along, word perfect.
But on closer inspection, it became clear that the only reason he wasn't sweating was a small battery-operated fan which he was holding under his chin.
I'd be prepared to bet a lot of money that no-one brought a handheld fan to the original gig.
The student who organised that concert - Simon Brogan, the then entertainments officer at Leeds University - was among the audience on Saturday night.
Back in 1970, Simon was an aspiring young academic seeking a career in the music industry.
What is he doing now? He is a sheep farmer in Scotland.
"It was the music for me which was the interesting part. The celebrity, the fame, the money wasn't what I was interested in," he reflected as he went into the concert with his wife, and three young sons.
More than 2,000 fans saw the group - formed in 1964 - on Saturday
A number of others from the class of 1970 were there, including Don Dunlevey, now a town planner in Leeds - and with much less hair.
His verdict on the 2006 concert: "It was fantastic. The first gig made me a Who fan.
"This one was probably even better because I'm older so I can appreciate it more."
Of course, there was one final issue to be addressed - how long will The Who last?
Two members of the original band are dead and the other two will soon be pensioners.
So is this current world tour the beginning of the end?
I foolishly put the question to Roger Daltrey, and received an earful of abuse.
"It was the beginning of the end in bloody 1969, what's the matter with you!
"I didn't think it would last 'til the end of the week."