Nash Ensemble, Wigmore Hall, London<img src="http://www.independent.co.uk/template/ver/gfx/threestar.gif"></img >

Under the Keatsian title of Realms of Gold, the Nash Ensemble has just embarked on an 11-concert survey of early-20th-century British chamber and vocal music, leading up to next year's celebrations for the 150th anniversary of Elgar's birth. True, the most rarely performed item of their opening Wigmore Hall concert, the Housman song cycle Ludlow and Theme by the composer-poet Ivor Gurney, was scuppered by the withdrawal of its soloist. But there was still much to enjoy - and to surprise.

Much surprise flowed from the sheer spontaneity with which such younger members of the current Nash line-up as first violin Marianne Thorsen and cellist Paul Watkins recurrently responded to one another and to the volatile pianism of the Ensemble's linchpin Ian Brown - never more so than in the opening item, Frank Bridge's Phantasy in F sharp minor for piano quartet (1910).

No matter how passionate or intricate Bridge's string and piano textures, they never clog or welter. This arch-form, one-movement structure with its darkly rhapsodic slower music enclosing a deftly syncopated scherzo shows how Bridge evolved his early style from such Continentals as Fauré rather than from English folk song.

After this, Thorsen and Brown took a time to settle into the wistful half-shades of Elgar's Violin Sonata in E minor, Op 82 (1918), though they managed the gentle caprices of its middle movement beautifully. Then violinist Matthew Truscott and violists Philip Dukes and Garfield Jackson joined Thorsen and Watkins for another rarity, Vaughan Williams's Phantasy String Quintet (1912).

This four-movement structure sets out in the modal manner of his Tallis Fantasia but also seems to pre-echo the idiom of his Fifth Symphony 30 years on, and is arguably better balanced than either of RVW's not-quite-satisfactory string quartets.

To make good the missing Gurney, Thorsen, Watkins and Brown fell back on one of their party pieces, Mendelssohn's Piano Trio in D minor Op 49 (1839). But there was nothing routine about their alternately surging, serene and quicksilver reading of this memorable music.