Where else to celebrate four decades of ABBA fanaticism than at the venue that hosted their vibrantly colourful entrance on to the world stage of pop at Eurovision 1974?

Forty years on to the day, our host for the evening was the irrepressible Christopher Green (Tina C and Ida Barr in other guises but on this night dressed initially in full Napoleon outfit) for whom this tribute/cabaret performance/illustrated lecture was clearly a labour of love.

The Brighton Gay Men’s Chorus lapped up the applause for their stylish renditions of Dancing Queen, Voulez-Vous and Knowing Me, Knowing You and they performed a brilliant skit on the perils of Eurovision voting.

We were also treated to two appearances by Valentina Monetta, San Marino’s entrant for Eurovision 2014, along with the slightly bizarre Martha And Eve, who re-worked Greece’s 1974 Eurovision entry, and the even stranger The Martini Encounter, re-imagining Olivia Newton-John’s UK entry Long Live Love.

There were eyewitness accounts and clips from the event with the host frequently inviting us to “re-live the moment in our heads”. But “douze points” really had to go to all those party people who dressed up for the evening and had a ball.