Theatre / The Fields of Ambrosia Aldwich Theatre, London

Funny life, being a travelling executioner, tootling around the Deep South with "Old Reliable" (ie the electric chair) in your jauntily painted van. You would, I suppose, be death's equivalent of an Avon lady: "Ding dong, anyone for a fry up?" Such a figure is the focus of The Fields of Ambrosia, a reprehensibly enjoyable new musical, set in 1918 - book and lyrics by its star, Joel Higgins, music by Martin Silvestri.

An ex-con who's gone about as straight as a hairpin bend, Mr Higgins' likeable scapegrace of an executioner, Jonas Candide, has a lovely chairside manner. As he straps in a condemned man, he makes a point of singing him a song about the paradisial future to which he is being dispatched: "The fields of ambrosia/ Where everyone knows ya". Admittedly, the heaven he paints might not be to everybody's taste. "You can sit by a creek and go fishin' for ever" conjures up visions of being stuck for eternity with a load of Anglican anglers.

As a musical character, Jonas is in a long line of charming frauds, outsiders whose relaxed disreputability brings the communities they visit to life. The twist, worthy of either Lope de Vega or some very lame movie, is that Jonas falls in love with his first female client, Gretchen, a young Austrian adventuress who may (or may not) have killed her last sugar daddy. Before you can say trip switch, Gretchen, who is sung with an intriguing timbre by the pure-voiced Christine Andreas, is trying to bypass her electrical fate via Jonas' crotch.

The second half of the show left this critic weak with bliss as it trampled over good taste and political correctness like a herd of bullocks. One way it tries to stick up for the "love" between the two main characters is to intimate that the prison is otherwise a hotbed of filthy perversion. A big, butch warder (Mark Heenehan), who is Jonas' violent rival for Gretchen's favours, evidently consoles himself with impressionable male convicts.

Marc Joseph's scrawny young mortician, a signal failure with women, finds himself raped by two prisoners. "If it ain't one thing, it's another" is the inspired opening line of his subsequent song about the family deprivation that has made him this isolated victim. Rarely, you feel, can loneliness have been quite so stagestruck, as you listen to Mr Joseph hollering "Alone, all alone". Certainly, his is a decibel-rich need that would empty rooms with some rapidity.

Often very funny in its own right, the show has a number of moments where it seems to be tone deaf to its own ridiculousness. To sing about letting sleeping dogs lie when you have a comatose rat on your operating table, as Michael Fenton Stevens's whisky doctor does, is to throw the cat among the pigeons, sense-wise. With high-voltage performances all round, though, and a strong so-bad-it's-good factor, this show makes a pretty sunny vacation from seriousness and propriety.