The banner told you that you were at the British International Motor Show Music Festival. Given, however, that this amounted to a helipad framed by three modestly proportioned grandstands and a stage, the word “festival” may have been pushing it a bit.

Previous evenings had paid host to the likes of Jools Holland and Deep Purple. On paper, an appearance here by the soft-rock titans Chicago seemed to have a lot going for it - at least it did while that paper neglected to mention that their best-known frontman, Peter Cetera, left the band some two decades ago.

Still, lest the bad news prompt revolt among those who had come to hear the 1976 überhit If You Leave Me Now, the band's de facto Cetera, Jason Scheff, bravely stepped up to the plate and sang it early on. Elsewhere though, there was little to suggest that they missed Cetera a jot. “In the early 1980s, we saw some big changes in the band, and that was a good thing for us,” declared the keyboard player Robert Lamm, stopping just short of adding, “because we were sick of having to plod through Peter's poxy power ballads night after night”. Instead, the eight musicians on stage played two slightly inferior power ballads - I Don't Wanna Live Without Your Love and Look Away - penned by the orange-faced, grey-haired keyboard player Bill Champlin.

Their attempts to convince the half-empty “venue” that post-Cetera life was a blast were rather more plausible during a succession of unloveable, brassy rockers which located a point of intersection between jazz, rock and R&B. Some, such as Questions 67 and 68 and Dialogue, dated back to the group's early years, when lyrics such as “Don't it make you angry the way war is dragging on?” made them briefly fashionable among countercultural circles.

That said, you suspected that in an exhibition space that had been made over to look like the inside of Jeremy Clarkson's head, ticket holders didn't care to be reminded about Chicago's credible history, less still about their recently released concept album Stone of Sisyphus. Nevertheless, when they finally got round to playing that album's title track, its resemblance to a sort of prog-rock version of Phil Collins's Sussudio seemed to strike a chord with people who had spent a humid afternoon perving at the new generation of Vauxhall Zafiras.

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