Taking on the Coliseum was, for Rambert Dance Company, either an act of supernatural foresight or outrageous temerity. Rambert had not shown its face in the capital for four long years, long enough for even the staunchest admirers to assume it must have quietly died a death like London Contemporary Dance before it. Would the fans register, remember and return? They did, and how. On Tuesday, Britain's longest-lived dance company - now celebrating its 70th anniversary - took the West End by storm. Under its latest artistic director, Christopher Bruce, the future of mainstream modern dance has never looked more glorious nor more certain.

In a birthday season the natural emphasis on Rambert's roots and longevity tends to dim the memory of past woes. The company was launched, as the Ballet Club, by the doughty Marie Rambert in 1926, and under her aegis it discovered and nurtured some phenomenal choreographic talents including Ashton and Tudor. When it hit a bad patch in 1966, Rambert herself took the decision to abandon classical repertoire to develop modern techniques. In 1991, it nearly sank again, following a drastic dwindling of audiences and the acrimonious sacking of its then director, the esteemed Richard Alston.

Now the bad times are past. But it is the strategy that Bruce has devised to override those pitfalls which gives the company its distinctive flavour. Gone is the earnestness that too often damped audiences' appetite for new dance. Popularist, cosmopolitan and theatrical to a fault, Rambert's new repertoire, built from scratch since Bruce's appointment in 1992, grabs you by the collar and doesn't let you go.

The week-long Coliseum season (two alternating mixed bills) showcased the reborn company's extraordinary range in works that make a nonsense of classical, modern and post-modern labels. In Petite Mort, Jiri Kylian's mordantly sensual play on the spirit of fencing, male dancers clad only in flesh-coloured corsets toy dangerously with gleaming foils as a calculating foreplay to suave entanglements with their female partners. In Ohad Naharin's larky Axioma 7, the entire company sits on stage like a row of Jewish tailors and plays a wild game of musical-chairs-cum-strip-poker, each chairless one catapulted into the limelight for an anarchic solo full of gutsy, grungey energy offset by sly humour.

Few other directors have either the contacts or the clout to buy in such a variety of world-class work from abroad. Bruce - by promising the highest possible production values - has in four years acquired an impressive portfolio. It helps, of course, to have the money to back the promises (and for this, three cheers for the Arts Council), but Bruce seems to have all the right priorities in place, including an eye for idiosyncratic, stylish performers and an unwavering belief in live music of tip-top quality as an integral part of the work.

Musical director Mark Stephenson and his band London Musici have become the sine qua non of the new Rambert's performance, honed for two seasons on a gruelling round of provincial theatres. Where most companies would feel justified in sticking on a record, especially in difficult music, Rambert bites the bullet: slow movements from two Mozart piano concertos in Petite Mort, the fiendish 4th Brandenburg for Axioma 7, Michael Nyman's saxophone concerto. The only score Stephenson passed on was the string of Rolling Stones hits for Christopher Bruce's Rooster, an affectionate, humorous backward look at rock'n'roll machismo - refreshingly non-PC.

In this company it mattered not that the only new work on show was a slight slip of a thing. Quicksilver, created by Bruce for the anniversary, pays tribute to the company's founder in a wispy memory-sequence of Dame Marie's youth set to Michael Nyman's sentimental film-score for The Piano. Young men exploring a dingy attic exhume an old trunk and start pulling out floaty antique clothes and then human rag dolls, two of which spring into life to re-enact biographical scenes. The piece gleams with Bruce hallmarks: surprising tilts, super-fluid phrasing and jazzy detail delivered with flourish. But just as Dame Marie's vivid personality almost burst the binding of her published autobiography, it also proves too much for this delicate creation. Quicksilver is indecipherable as a story and sketchy as a character study. As pure dance it merely tickles the palate for more. But there will be more from Rambert, that's for sure.

'Rambert: a Celebration' is published by Rambert Dance Co, pounds 15.