National Youth Orchestra of Great Britain, Daniel, Leeds Town Hall

Middle-period Mahler can be hair-raising enough under normal circumstances. In this performance of the Fifth Symphony, the angst and intensity dials had been turned up to 11. Every orchestral colour shone with greater intensity, and each change in dynamics registered with piercing clarity. Which could only mean that this year's freshly reconstituted National Youth Orchestra of Great Britain were giving their first concert of the season.

Half of these musicians have only been playing in the NYO for less than a week. That the quality remains so consistently high each year is remarkable – credit is due to the orchestra's musical and pastoral backstage staff. Close your eyes and you'd think that you were hearing an elite European band at the top of its game. Open them and you gaze in wonder at 163 fairly normal-looking adolescents, playing out of their skins.

Mahler's 'roaring, raging sea of sound' was terrifyingly visceral

Manchester-based composer Larry Goves's The Rules was a brilliantly bold opener, though you suspect that the work's unfamiliarity might have been responsible for the alarming number of empty seats. Goves's 25-minute work began life when its composer considered what an updated Young Person's Guide to the Orchestra might sound like, while ensuring that the resulting music's complexity was never diluted for younger players' benefit. Heard in a perfunctory reading by jaded professionals, it mightn't have had much impact. Here, under Paul Daniel's baton, it gripped as a convincing musical structure and as a virtuosic demonstration of how a large symphony orchestra can still produce wondrous sounds in skilled hands.

Watching Daniel's clear, unfussy beat direct music of fiendish rhythmic complexity was unsettling, before you sensed that at several points, whole instrumental sections were seemingly left to their own devices, the various layers overlapping like different coloured acetate sheets. Which will only work if you have an ensemble where the players really listen to one another; despite the huge forces involved, you never felt bludgeoned into submission. There's a remarkable unison melody in the second section, heard in tandem with metronomic, ticking percussion. Goves's sense of structure and timing is shrewd; the work ends suddenly, unexpectedly, leaving you wanting an encore of the whole thing.

Alas, this wasn't possible; after an interval it was time for the Mahler. Matilda Lloyd's halting, edgy trumpet solo was among the best I've heard in this work, as if she was consciously galvanising the orchestra into action. With a 90-piece string section and massed wind and brass, some of Mahler's finer detail was inevitably lost, but the gains were massive – the first movement's string lines are rarely this audible, and Mahler's “roaring, raging sea of sound” was terrifyingly visceral. Juicy brass chords raised goose-pimples.

Daniel managed to remember Mahler's quieter corners; the second movement's soft cello threnody was immaculately phrased. Principal horn Joel Ashford didn't have space to play the third movement's obbligato at the front of the stage, so had to compromise by standing up behind the strings. He was terrific, and the lonely soliloquies at the movement's heart have rarely sounded so poignant. Fast speeds led to a few moments of rhythmic untidiness, but Daniel avoided disaster.

I liked the swiftness of the Adagietto; here presented as a sweet, affectionate love song, all excessive sentiment scraped away. Mahler's joyous Rondo Finale was nicely paced – gloriously rich and ripe, but with no hint of brassy bombast. Watching eight immaculately synchronised trombone slides move during the closing chorale has to be witnessed. It was a flawless, exuberant evening. The same programme is repeated at London's Barbican this evening, so start queuing for returns now.

• At the Barbican Hall on Sunday 5 January 2014