John Lennon would, as we all by now know, have been 70 last weekend. For those who find that a bit hard to take, there are more rock legend septuagenarians right behind. Next year, it's Bob Dylan's turn. Paul McCartney turns 70 in 2012, and Mick Jagger in 2013. It's a sobering thought that the Sixties rock stars have reached that birthday. It does prompt one to wonder if it's an age that will put paid to performing. Once one would have thought so, but then once one would have thought 60, 50 even 40 would have done so.
What's certain is that 70th birthdays are an enticing thought for the record companies as they scour and repackage the lucrative back catalogues.
In Lennon's case, last weekend marked the first of two anniversaries this year. In December, it will be 30 years since he was murdered, and that will provoke another rash of articles and maybe even albums, if there is anything left to be repackaged and remastered.
For the 70th-birthday jamboree, Lennon's solo albums were remastered by his widow, Yoko Ono. I hope it does not appear to be disrespectful, not too disrespectful, if I observe that Yoko Ono is not known as an expert record producer or engineer and it is a little strange that she was in charge of the remastering.
But then she seems to be in charge of much of the celebrations surrounding her late husband, which perhaps is why they only seem to concern one section of his life, and why only his (extremely variable) solo albums are being re-released, and why the lavishly packaged commemorative Box of Vision, which is also on sale alongside the albums, has booklets and lyrics that have almost as many pictures of her as of him – and not one, single, solitary picture that I could see of that not insignificant band he once played in.
What would he be like if he were alive now, she was asked at the weekend. "He would have been very, very angry that violence and war were still going on," she replied. Well, yeah. But I suspect he'd also have something funny to say about The X Factor and Lady Gaga.
Will the only John Lennon that future generations are going to see and hear about be the solemn, bearded peace campaigner (even his first wife, Cynthia, and son, Julian, opened a peace memorial in Liverpool at the weekend)? Is the only period of his life and his music sanctioned for discussion and memorabilia that of his second marriage?
Certainly this sombre version of Lennon, and indeed the serious, embittered bloke played by Christopher Eccleston in a recent TV biopic, are unrecognisable to friends of the man, who have told me that the Lennon they knew, even during his campaigning period, was a constant joker and wit.
He also needs to be remembered for that rather important body of work he helped make before his solo career, the body of work that invented and then transformed modern pop. So if you want to have a blast of the real John Lennon to mark this anniversary, find some old Beatles records, listen to songs like "Any Time at All", "I Feel Fine" or "No Reply" from the early mop-top days for raw-edged, melodic pop, then see how pop was redefined to include lyrical introspection and musical experimentation with the likes of "Happiness Is a Warm Gun", "Strawberry Fields Forever" and "I Am the Walrus" from the middle period.
I'm not a great fan of celebrating pop anniversaries. They are usually an excuse for fans to be relieved of their money for a set of albums they already own with some imperceptible, small differences and superfluous packaging. I'm even less of a fan of anniversaries when they offer an uncomfortably selective tribute, which does pop history no favours.