Robert le diable, at Royal Opera House, review For that reason alone, it merits serious and stylish rediscovery. At Covent Garden, some modest snipping may be understandable - running time is already four-and-a-half hours - yet such cuts as chunks of the fourth-act finale only leave the piece in a weakened, patchwork state. Practicality also dictates the conductor Daniel Oren's decision to use regular instruments rather than follow some of Meyerbeer's more exotic demands, but the work's colours are compromised. At least, the much-vaunted ballet of zombie nuns registers vividly, despite being undermined by Lionel Hoche's tacky choreography. Staging this tale of a supernatural struggle between good and evil - Robert "the devil" is the son of a beautiful princess and a demon - cannot be easy, but it would help to have a director who takes the task seriously. Instead, the ubiquitous Laurent Pelly stages another of his facile shows, in garishly bright, cod-medieval costumes: the Devil wears Quality Street. Chantal Thomas's toy-town set is so ill-fitting that it looks as if the French team submitted their designs in metres, only to have the Covent Garden workshops build them in feet. Though the craggy mountain in Act 3, complete with its souls burning in hell, approaches the spectacle required, it is ironic that the climactic church scene in Act 5 falls far short of the exciting realisation it apparently received at the 1831 premiere. Bryan Hymel has impressive stamina, if not much subtlety, in the taxing title role. Marina Poplavskaya veers in and out of focus as his sister, Alice, while John Relyea lacks the sepulchral bass required for his father, Bertram. Jean-François Borras makes a good Covent Garden debut as the minstrel Raimbaut, but there is something odd about the casting when the star is also the 11th-hour replacement: as Robert's betrothed, Isabelle, Patrizia Ciofi spins dazzling coloratura. To Dec 21; www.roh.org.uk