Prom 50: Collins, BBCSO, Vanska, ****/ Prom 51: City of Birmingham Symphony Orchestra, *****

With eight exhumations, the BBC is trying desperately to make the case for Frederick Delius on his 150th anniversary, but these are only reinforcing the impression that this Bradford composer was a mere melodious also-ran.

Prom 50 brought his "Eventyr (Once Upon a Time)", intended as a ‘ballad’ evoking the folk tales and his beloved Norway; its colourful path was twice interrupted by recordings of massive male-voice choral shouts designed to suggest the irruption of giants and demons. This effect was undeniably disturbing, but not in the manner the composer intended, and two weird shouts don’t turn a piece of amiable hackery into a masterpiece.

But everything else in this concert with the BBC Symphony Orchestra under Osmo Vanska was first-rate. After a finely-chiselled account of Beethoven’s "Egmont" overture they were joined by Michael Collins, armed with a basset clarinet to render the deeper sounds in Mozart’s "Clarinet Concerto in A major".

Collins’s virtuosity was typically relaxed and unshowy, with an exquisite sense of line and shading; Vanska’s expressive beat drew such fine playing from the orchestra that the whole thing acquired an air of enchantment. And in Carl Nielsen’s intricate and fascinating fifth symphony, Vanska revealed how vividly the traumas of the First World War had impregnated this work, with its ominous side-drum threats and ferocious clarinet shrieks punctuating hopeless instrumental pleas for peace.

The novelty in Prom 51 was Emily Howard’s "Calculus of the Nervous System", a slight work with heavier literary and neuro-scientific baggage than it could bear, or needed to: its form, we were told, was a ‘neural network, with no continuous narrative’. All stops and starts, sometimes on the edge of audibility, sometimes crashingly loud, with wispy ideas pursued from section to section of the orchestra, it conveyed a vague sense of urgency, and indeed no forward movement. Taking my cue from the gagaku-style dissonances, I found myself imagining a Zen rock garden in Japan, which the music fitted very pleasantly.

If Andris Nelsons and the City of Birmingham Symphony Orchestra made a good fist of this, they excelled themselves with Shostakovich’s "Leningrad" symphony, which came over in as majestic a blaze as I have ever heard. Wonderful wind soloists, superb strings, percussion letting loose the dogs of war: a magisterial performance which richly deserved its ovation.