From boy-band escapee to laddish, rehab-prone addict to stadium-filling superstar, no British pop icon can have grown up in public quite so spectacularly as Robbie Williams. Yet as he slides into middle age at 40, the once troubled artist appears to have settled, finally, into his natural role as a consummate all-round entertainer.

Promoting his second swing-based album, last year's Swings Both Ways, Williams fronts a vibrant show that is part Vegas revue, part standup comedy and very large part 1970s TV Seaside Special. It's difficult to envisage a gig by a music A-lister that is less po-faced, less concerned with being hip, or more preposterously entertaining.

Perennially self-mocking, Williams reminisces on his 90s imperial period as "a fat Justin Bieber" before soaring above the crowd in a fat suit to deliver the faux-operatic No One Likes a Fat Pop Star. After a mock wedding with a fan from the crowd, conducted by the Reverend Guy Chambers, his donning of a Planet of the Apes-style monkey mask to gibber through the Jungle Book's I Wanna Be Like You appears positively decorous.

The night is not all looning slapstick, and Go Gentle, Williams's self-penned paean to his 18-month-old daughter, Theodora, is genuinely heartwarming. Equally endearing is his preening duet through Duke Ellington's Do Nothin' Till You Hear from Me with his father, Peter, a nightclub singer from whom he is palpably proud to have inherited his crowd-pleasing genes.

It's a simultaneously subversive and affectionate take on ye olde variety show, and Williams, mugging, cracking gags and drenched in sweat from the off, is an old-school showbiz trouper right up to his show-stopping drawl through Angels. If anybody this year stages a more fun, up-for-it pop gig than Robbie Williams, I would love to see it.

• Until Saturday. Box office: 0844 856 0202. Venue: O2 Arena, London.