Proms: RUDERS / NIELSEN / LUTOSLAWSKI / DVORAK Royal Albert Hall, London

Out of the closet and into the limelight. One day you're the butt of everyone's bad jokes, the next their favourite instrument. Three concerto premieres in almost as many months, and more, no doubt, where they came from. The viola is back in the ascendancy. So is that an end to the sexual identity crisis (Sir Thomas Beecham called it "the hermaphrodite of the string section"), the "mister (or is it miss?) in-between" syndrome? I'm sure players like Yuri Bashmet and composers like Poul Ruders wouldn't know what you were talking about. It's true, the fascination of the instrument has always lain in its ambiguity, its elusive, mysterious timbre. But its expressive potential, its reach, its powers of persuasion and command are there for the unlocking. Limitations? What limitations?

In his recent Concerto for Viola and Orchestra (I993-4) - here receiving its UK premiere) - Poul Ruders will have none of it. He begins as he means to go on - in extremis. The viola hasn't had an entrance like this since... well, ever? Solo and centre stage, his opening soliloquy-cum-confessional is already at a high pitch of intensity when we join it. The tone is forceful, impassioned. This most private, inward-looking of instruments is going public. Yuri Bashmet's big, open sound suggests no more secrets. The spirit is willing but restless, the manner anxious and beseeching. And from this central source or life-force, thematic ideas (and their derivations) begin to seep into and proliferate through the orchestra, radiating, as it were, from the soloists stream of consciousness.

It's very much a "quest" piece (aren't they all?), journeying towards the unknown region in search of answers - peace of mind, body, and soul. And it's a tribute to the compelling emotional current of Ruders' music - one of his great strengths - that so long a journey (almost 30 minutes) is so well sustained. The textural intrigue, the iridescent colours are, as ever, most striking. The still centre of the piece (glimpsed again towards the close) finds the soloist suspended amid gleaming, other-worldly violin harmonics, his quiet ruminations placed right in the middle, the heart of the instrument. Sublimation appears to come with one final pitch for the light, the soloist soaring comet-like to a luminous high-point. But six octaves below, the ground-bass has shifted to create the kind of ambiguity we find at the close of Sibelius's Seventh Symphony. A hopeful pessimism?

Ruders' Concerto is surely now as taming as any in the expanded viola repertoire. The effusive solo line barely pauses for breath. But then, stamina was always Yuri Bashmet's middle name. Ruders' home band, the Danish National Radio Symphony Orchestra under their chief conductor Ulf Schirmer, lucidly worked the intricate orchestral polyphony. Schirmer has a nose for dramatic incident. Nielsen's Fourth Symphony "Inextinguishable" was conspicuously fine: spacious and atmospheric, possessed of the right sweep and surge factor. Though I'm not altogether sure that the dramatic late arrival of the second timpanist just in the nick of time for the finale's famous confrontation was quite the kind of theatre Nielsen had in mind.

The late Witold Lutoslawski might have been born a Frenchman. The elegance, the fine-tuning of his music has much in common with that nation's creative sensibilities. His 1988 Piano Concerto even pointedly recalls the spiky E-flat clarinet and bluesy trumpet slurrings of the Ravel G major Concerto. Actually it's full of allusions to the past history of the genre, the noble rhetoric of Brahms, the baroque-inflected recitatives of Bartok - indeed all the gods in Lutoslawski's pantheon - but shot through with his very particular fastidiousness. Ursula Oppens played it at Tuesday's Prom with a cut-glass clarity, a rich appreciation of all its crystalline configurations. Franz Welser-Most and the London Philharmonic were punctilious, the orchestral texture vital and alive. Earlier they excelled in a splendid account of Dvorak's too rarely heard tone-poem The Water Goblin. Welser- Most's patience was a major factor here - the lyricism yielding and long- breathed. A glimpse of the Welser-Most of old?