Forever Young, BBC Four

Appropriately enough, Forever Young began with the primal beat of Iggy Pop’s “Lust for Life". What I consider to be Mr Pop’s “My Way” seems to perfectly sum up the pumped-up and apparently unstoppable forward momentum of the man himself and his against-all-the-odds lengthy career. But it could just as easily represent many of the world-weary yet resilient musicians interviewed in this unexceptional but nevertheless diverting documentary.

Along with Iggy was the always-available-to-reminisce-to-camera Rick Wakemen, plus Robert Wyatt, Robin Hitchcock, Eric Burdon (or was it Fungus the Bogeyman’s dad?), Peter Noon and a few other pensionable pop musicians who had thought long and hard on a question closest to their hearts: how do you justify still taking to the stage to sing about drugs, youth, chicks and rebellion when there are killjoys out there who think you should have died dramatically and/or tragically in 1973, thus securing a more dignified and legendary status for yourself?

For this was the main thrust of Forever Young. The bands still want to rock, the audiences - both young newcomers keen to see a living legend, and old nostalgists, keen to revisit their past - still want to rock with them, so what’s the problem? Well, the problem to a degree is documentaries like this. Although at least this documentary gave a few old rockers the right to reply, and pretty good they were at it too. Coming on like Noam Chomsky, Iggy explained in his measured baritone that it’s always been about “the seizure and the marketing of a folk movement by the same commercial and industrial forces that take anything and tries to identify the most defenceless consumer to sell it to". And this is the guy who sang, “I Wanna be your Dog”! He may still throw himself around the stage like an unhinged teenager, but at least Mr Pop likes to ruminate on the reasons why.

There’s something of the Greek tragedy about the idea of our once dangerously beautiful rock stars growing old, yet the subject is normally approached as comic rather than tragic, with vulture-like critics taking pleasure in imagining the likes of Jagger and Richards shuffling onto the stage for their 400th world tour clutching Zimmer frames. Yet these same critics will watch in awe until their favourite old African-American blues singer crumbles into dust before their eyes, before admitting that Blind Lemon Jackson or whoever can’t growl quite as authentically as he used to.

But this documentary didn’t really touch on such hypocrisies. Instead we got a potted history of pop music, from poppy pop, to taking-itself-too-seriously pop, to national institution pop, and back to poppy pop again, and how these changes have affected this bunch of valiant survivors who’ve miraculously continued their dream careers through four or more decades, having initially expected to be “back on the coal” after six months. Unfortunately, although the Stones inevitably came up a lot, all Stones were left unturned, as no new footage of Jagger and Co was captured. But there was one amusing clip from 1981 in which Jagger responded to the usual question, “How much longer can he go on with performing this high-energy show?” with, “For another five years, maybe.” However, the best answer as to why Jagger is still rockin’ and mincin’ with as much preternatural energy as he’s ever done - nearly thirty years on from that interview - was given by Lemmy who said with the incisiveness of Descartes, “How is it possible to stop? It’s what I am.”

But in a program which mainly consisted of cavalier but essentially unrevealing reflections on aging in a youth-orientated market place, it was only Robert Wyatt who said anything of real emotional resonance.  He spoke with feeling of the two very different versions of Joni Mitchell’s “Both Sides Now”. The first, recorded in her twenties, brims over with wide-eyed innocence and hippy optimism, despite the song’s melancholy bent. Whereas the second, recorded in her mid-fifties, is weighed down with a lifetime’s worth of experience and pensive, ominous orchestration. It was as if, as Wyatt put it, she finally understood the song she’d written all those decades ago. Clips of both versions were segued perfectly into each other to disconcertingly moving affect, prompting me to imagine what the whole programme would have been like if it had had a bit more gravitas. But with Cherie Lunghi narrating with the cheery unintentional condescension of a 1950s childrens' television presenter (I expected Andy Pandy to pop up at any moment to tell us what really happened at Altamont), there was never much hope of that.

Here are those two Joni Mitchell performances in their entirety