Still going strong ... Neil Tennant
of the Pet Shop Boys. Photograph:
Linda Nylind

Look at the music listings for the summer and you could be forgiven for thinking that it was 1986, writes Chris Johnston. Billy Joel, Roxy Music, Tom Jones - all still strutting their stuff 20 years on.

With the Rolling Stones still playing to over a million fans more than 40 years after their first gig, it might seem ridiculous to question whether bands should keep going long after their golden years are over.

It's certainly not something that appears to worry groups such as INXS (who simply replaced their dead singer) or the Who (who have just embarked on a world tour), as long as there are people willing to fork out extortionate sums for tickets.

Another veteran act on tour this summer are the Pet Shop Boys, who played their first London gig in four years this week at the Tower of London.

With a well-received new album, Fundamental, in the shops - if no longer in the top 40 - the Pet Shop Boys are one band that can't be accused of simply milking their back catalogue when playing live.

The duo kicked off with Psychological, the opening track on the new album, and their brilliant set included the epic The Sodom and Gomorrah Show and forthcoming single Minimal. This provided one of the concert's most electric moments as it merged into Shopping, which still sounds remarkably contemporary despite being recorded in 1987.

Unsurprisingly, the biggest cheers were for the hits - West End Girls, Opportunities (Let's Make Lots of Money), It's A Sin, Go West. And admittedly, most people want those rather than a track-by-track rendition of a band's latest record.

But when fans only want the hits and aren't interested in hearing - or buying - the new material, should it be time to take a hint and give up?

One of the singles lifted from 1993's magnificent Very album was the tongue-in-cheek Yesterday, When I Was Mad. On it Neil Tennant sings: "And someone said: 'It's fabulous you're still around today/You've both made such a little go a very long way".

To have survived 20 years in the fickle world of pop means that the same cannot be said of the irrepressible Pet Shop Boys. The same is not true, however, of some of rock's other veterans.