Alice and Ellen Kessler, who died by joint assisted suicide this week, entertained – and occasionally scandalised – Europe with their glitzy and subversive pop music and classically informed dance

• The Kessler twins die together aged 89 – news

When Dean Martin announced the Kessler sisters’ appearance on his show in 1966, he remarked that he had been desperate to book them not just because the German-born dancer-singers were “so pretty and so talented”, but “also because they’re twins, that means there are two of them”. “They’re a double,” he added with a nod to his half-drunk crooner persona, “and there’s nothing I like more than a double”.

The two sisters, who died by joint assisted suicide earlier this week, also performed with Frank Sinatra, Harry Belafonte and Fred Astaire, but the American market never impressed them much. In 1964 they turned down a role in Elvis’s Viva Las Vegas for fear of being pigeonholed in American musical comedies.