With no sign of Abbamania abating, Radio 2 threw a party in Hyde Park to celebrate the nation’s fascination with “the Swedish Fab Four”, as the host, Chris Evans, called them. Thank You for the Music featured a bill so wilfully diverse and a camped-up audience so expectant of a singalong that it felt as if the acts were competing for points on a clap-o-meter.

Few dared meddle with some of the most famous arrangements in pop, though Jamie Cullum came unstuck by tinkering with the tempo of My Love My Life alone at piano and VV Brown’s supposedly sultry Ring Ring fell flat. Most of the 20 odd acts in a two and a half hour set broadcast live were backed by both the BBC’s vast Concert Orchestra and an “Abba band”, that occasionally included Benny Andersson. Hence, changeover times were just long enough for an on-form Evans, sporting a red wig and silver jumpsuit, to dole out Abba facts and to chat to the likes of Tim Rice.

While some of the pop singers struggled against the might of an orchestra, a fabulous Capital Voices choir soared, Elaine Paige and Siobhan McCarthy proved the power of voices more used to musical theatre, and a three-song medley from the London cast of Mamma Mia! went down a storm. Less so a new number, Rowing on the Serpentine, written by Andersson and Björn Ulveaus, inspired by Swedish folk music and featuring five fiddlers.

Chaka Khan had been flown in from America to sing The Winner Takes It All, though probably not in the frighteningly tight corset dress she wore on stage. Her belting performance was the night’s pop highlight — think of Abba as a Bassey-like Bond theme — and it was a shame she wasn’t on for longer.

The unofficial headliner, Kylie Minogue, in her only live UK performance this year, claimed it was “a dream come true” to sing Abba and had set her stylist to work. Her sparkly, disco jumpsuit, Farrah Fawcett-flicked hair and blue eye shadow almost outshone her fun, faithful rendition of Super Trouper. She returned in a flowing white dress and sat beside a besotted-looking Andersson on piano for the sweet ballad When All is Said and Done, which verged on saccharine, but was lapped up by the crowd.