There was a palpable sense of anticipation in Eden Court's splendid new One Touch Theatre on Friday night. After the much-vaunted, two-year Highland Quest For A Musical, the winner, The Sundowe (by brothers John, Gerry and James Kielty) was finally being unveiled.

The brainchild of musical theatre impresario Sir Cameron Mackintosh, the Quest was a genuinely mammoth project. Books and musical scores were received for 140 new musicals. A huge team of readers narrowed that down to 43, from which the selection panel chose The Sundowe as the grand finale to 2007, Highland Year of Culture.

So is it any good? The Sundowe is astonishing, but not in a good way.

The cause of the astonishment is that the Kielty brothers' misconceived mess of a musical made it into the longlist, let alone on to the stage as the winner of a major competition.

One feels a flood of sympathy for the Quest's selection team: how much unutterable nonsense did they have to wade through if this adolescent, badly written theatrical dog's dinner was the best thing on offer?

Set in Edinburgh, the piece follows the intrepid adventures of a band of buskers called The Martians (played by Kieltys John and Gerry, and a performer known only as Houston). The plot involves the anti-busking legislation of the Minister for Cultural Reform (Madam Godwin, a politician-cum-dominatrix, played by Cora Bissett); a centuries-old, undead ghoul-catcher by the name of Roothby (Crawford Logan); the blood lust of some reawakened vampires; and the apocalyptic rising from the grave of the denizens of Greyfriars Kirkyard.

The Kielty brothers' musical is part video for Michael Jackson's Thriller, part Doctor Jekyll and Mr Hyde-style gothic, part Rocky Horror Show kitsch. Sadly, however, the show comes nowhere near achieving the musicality of Michael Jackson, the literary merit of Robert Louis Stevenson, or the comedy of Richard O'Brien's cult musical.

With its various, interwoven storylines the plot is convoluted, overloaded and regularly incoherent.

Musically, the piece is insipid and utterly unmemorable. It is, surely, one of the hallmarks of a good musical that one finds oneself humming its tunes in the bath. There isn't a single song from The Sundowe that one hasn't forgotten by the time the curtain comes down.

In fairness to director Kenny Ireland, there was very little he could do with the drivel he was given. He has, remarkably, been able to convince his cast to play the piece with energy and, at times, skill (Bissett, in particular, is in fine voice).

The fact remains, however, this witless musical is a bitterly disappointing conclusion to a major project, and a criminally missed opportunity for theatre in the Highlands.

At Eden Court Theatre until December 15. Touring the Highlands, January 15 to February 2