Zipp!, Duchess Theatre, London

Now then class, who knows what a list song is? Yes, it's one of those songs featuring a succession of fantastically rhymed variations on the same lyric idea. And if you've seen Anything Goes you'll have heard Cole Porter's most famous one. It has a staggering seven refrains, the second of which begins: You're the top!/You're Mahatma Ghandi/You're the top!/You're Napoleon brandy...

I mention this because although Zipp! contains not one list song, its entire premise is a list. The ex-sweater-wearing MP for Chester, Gyles Brandreth, has written himself a vehicle running through 100 musicals in 90 minutes and the good news is that he has a strong pianist/arranger in Stuart Barr. The bad news is, well, everything else.

The three other cast members are game and sing (mostly) in tune, but Brandreth goes from hectoring to ingratiating and winds up self-satisfied. As for the material, truly great musicals are rare but there are thousands of notorious duds and flops so surely he's come up with some good gags? No. The Sweeney Todd sequence is built around the rhyme: "He's got a chopper/ Oh it's a whopper." If schoolboy innuendo is your bag, book now. OK, so The Sound Of Music section raises laughs out of blonde plaits and daft props, but SingalongaSoundofMusic is (approximately) ten thousand times funnier.

Who is this shoddily directed show actually for? If you hate musicals, you won't get the in-jokes. And if you love them, either you want better gags or you want more than couplets from a 100 odd songs. We're promised the showstoppers without the tedium of the show. If only.

Zipp!, er, climaxes with a number from Annie Get Your Gun. When Suzi Quatro starred in the West End revival, cast members referred to it as Annie Get Your P45. Gyles, take note.

Duchess Theatre, London WC2 (0870 890 1103) to 26 July