Since it began in 2006, the English Music festival has thrown valuable light on some undeservedly neglected British composers. But it would deserve a lot more attention, and get taken just a bit more seriously, if its scope were not quite so obviously conservative, and if it showed itself just as keen to revive forgotten works by Humphrey Searle and Elisabeth Lutyens, say, as it has been to resuscitate the likes of York Bowen and Joseph Holbrooke.

Yet the four-day festival is undoubtedly resourceful about coming up with novelties – this year’s opening concert, given by the BBC Concert Orchestra conducted by Martin Yates, contained two premieres. George Butterworth’s Fantasia for Orchestra received its first ever performance, though that was not the major discovery it promised to be. When he left to fight in France, where he died in 1916, Butterworth destroyed a number of unpublished works, but he preserved 92 bars of his unfinished orchestral fantasy. Yates has completed the fragment, elaborating it, with alternating fast-slow-fast sections, into a 17-minute work. It is a seamless piece of musical speculation, though more impressive in the brooding outer sections than the folksy faster music that Yates has inserted between them.

The concert had begun with the first British performance of Richard Arnell’s New Age Overture, composed in the US in 1940 and showing an unlikely fusion of Vaughan Williams and Hindemith. That was followed by authentic Vaughan Williams – the early Bucolic Suite – and Havergal Brian’s English Suite No 3. But the real substance came at the end of the concert with Finzi’s Cello Concerto, in which the soloist Raphael Wallfisch made no attempt to disguise the music’s elegiac qualities (it was Finzi’s final work), nor its Elgarian echoes.

• The English Music festival continues until 25 May.