Thomas Arne, born and buried in WC2, would be an apt patron composer for the annual BOC Covent Garden Festival. He might also be the most frequently sung of British composers, with God Save the King and Rule Britannia to his credit. It is for finishing with Rule Britannia that Arne's Alfred, written in 1740, is best known.

Today all the other choruses and the recitatives are lost, making it difficult to stage the work in a satisfactory way. Certainly the performers found it hard to maintain dramatic flow when the vocal numbers didn't lead naturally from one to the other and there was no recitative to connect them musically - or to explain what was going on in the story.

In Netia Davan Wetton's characteristically bold staging, in the Linbury Studios of the Royal Opera House, baroque music theatre met MTV. Stylised images, constantly moving and flickering, were projected onto a screen behind the characters. The dancers Floyd and Damian Hendrix acted out skirmishes between King Alfred's forces and the invading Danes as a fluid cross between kick-boxing and breakdancing. Yet for all Davan Wetton's audacity, her designs and direction were most successful when they were at their simplest. Critics at early performances complained of a lack of stage action in Alfred; but here the action often had the effect of drawing attention away from the music.

The music certainly deserved the audience's focus. From the harpsichord, Christian Curnyn directed a crisp, spirited and accomplished baroque orchestra. Alfred may be perceived as a one-hit wonder, but there are some fine arias, in particular a revenge number for Alfred's wife, sung by Elena Ferrari, and - the most beautiful - a touching song of filial love from his son Edward, sung with unaffected elegance by Sally Bruce-Payne. A subdued episode in which a woman mourns her dead husband had seemingly little place in the sketchy plot, but provided a welcome opportunity to hear Louise Mott, a polished and expressive mezzo.

Alfred himself, sung by tenor Daniel Norman, began wearing shirt sleeves, waxed jacket and the look of a slightly bewildered back bencher. A more regal bearing - and a stronger voice - emerged in the second act, without which the Danes would certainly have been the favourites in this particular battle.

• Ends tonight. Box office: 020-7413 1410.

***** Unmissable **** Recommended *** Enjoyable ** Mediocre * Terrible