When Iolanthe in 1882 became the fourth consecutive major success for Gilbert and Sullivan, Gladstone, a Conservative-turned-Liberal, was prime minister and women had no vote.

The London theatre scene could easily manage without another musical about love. But the UK premiere of this Australian-born celebration of the greatest of emotions by Peter Rutherford and James Millar is nevertheless as welcome, even as necessary, as every generation’s attempts to redefine love for themselves.

As far as 1960s audiences were concerned, Lionel Bart – famed for the musical Oliver – had lost his “twang” when he came up with the box office flop “Twang!!”, with two exclamation marks. But if the audiences of the swinging sixties weren’t ready, the 21st century theatre-goers of London’s Union Theatre – renowned for alternative, low-budget, high-entertainment musicals – are.