DANCE: Tharp! ; The Edinburgh Playhouse

Everyone always expects great things from Twyla Tharp. Her 30 years of consummate dance-making have combined technical virtuosity and keen intelligence with the shameless appeal of vaudeville and her eager and grateful audiences always hope that past triumphs will be repeated. The triple bill at the Edinburgh Playhouse did not deliver a masterpiece but seemed to show us a choreographer in transition: straying into new territory, then retreating to the familiar safety of her tried and tested dance language.

Heroes is danced to a score written by Philip Glass with her dancers in mind. He plays a game of loaves and fishes with David Bowie and Brian Eno's Seventies hit, taking the pop melody phrase by phrase and using it to feed 40 minutes of dance. Unfortunately this particular composition is not rich enough to benefit from such close analysis and the resulting score is dull and rather sentimental. You don't notice this at first because the flatness of the score is masked by the magnificence of the dancers.

Our heroes pose in silver trousers and black shorts and their sequence of mock fights examines manly aggression and boyish insecurity. The pirouette- like tornadoes cross the space then freeze in punishing balances: Matt Rivera is frequently tormented by a pose in which he raises his leg in a high extension then jacks up the pain index by suddenly flexing his foot. All in a day's work for dancers of this calibre. The five women rush into this choreographic locker room as if attempting to break into the cycle of narcissism and machismo. One's heart sinks to see Julie Stahl hurl herself horizontally at a wall of obdurate muscle only to slam to the floor: surely this is a dance language spoken only in places you don't want to visit. The dancers contrive to flatter the choreography, while Jennifer Tipton's flattering lighting is that magical, imported kind that can make a performer glow in the dark.

The second piece, Sweet Fields, takes place in a sunny pool of dappled light in which beatific dancers skip and play to the sturdy Shaker hymns of William Billings. In the clean, white garments of the hymn, they tread gay, flat-footed measures. The audience loved it but it left me cold. The folk-dance pastiche is too literal and the lack of any discernible wit in the treatment makes the skipping, smirking dancers appear simple- minded. An attempt is made at humour by the time we reach "New Jerusalem", when the dancers give each other swift back-massages and execute various raunchy pelvic gyrations that sit uneasily with Billings' honest piety - like a see-through blouse in church.

The finale was 66, danced against a backcloth showing the famous highway cutting a swathe across the map from Chicago to LA - a journey Tharp herself made as a child. The work is danced to "bachelor pad" music of the Fifties and Sixties and the sole justification for its existence is the relationship between Julie Stahl and Andrew Robinson. Their series of duets is a super- charged jitterbug that charts their relationship, from early flirtatious days through rough patches and on to apparently lasting fulfilment. The dancers are sensational and the eager, laddish Robinson wears his talent very lightly - a manner well suited to this insouciant house style. It is a pity that Tharp has yet to make her new dancers the works they really deserve. Louise Levene