Mahler is never one to shy from a confrontation with the human mind in his music; his Symphony no. 1 “Titan”, which formed the second half of the LSO’s Sunday night concert at the Barbican, draws on the literature of German romantic Jean Paul to encapsulate the mindset of an heroic, passionate genius. Huw Watkins’ Flute concerto, in its world première performance by flautist Adam Walker, provided a less idealised musical representation of a more real human subject under considerable psychological duress. Its layered subtleties proved as immensely powerful as the symphony at its most “titanic” in what was a spectacular concert, superbly directed by Daniel Harding.

Watkins’s new concerto is an intense work that not only seems to explore (and express) the multiple states of mind of an agitated human subject, but also draws on and develops the personality of the instrument. Although the flute’s songfulness is perhaps the musical aspect with which it is most commonly associated, here it is not so much its lyricism but its flightiness which Watkins brings to the fore. Walker invested the music with great nervous energy. This is not the flight of a freely fluttering bird, but an anxious, caged one; although occasional hints of Vaughan Williams' harmonies beneath the rising flute line caused one to glimpse larks hovering over fields. Predominantly, however, in the first and third movements the soloist’s swirlings and scurryings are set against contrasting sonorities in the orchestral parts, whether robust tutti textures, the plummeting depths of the growling contrabassoon, or the ethereal sustained notes in the upper strings.

It is in the interplay between soloist and orchestra that Watkins weaves his extraordinary psychological web, providing the audience with a rich backdrop against which the flute’s agitation gains poignancy and profundity. Towards the end of the first movement, for example, the flute flirts with middle-eastern scales, while a shift in orchestration prompts it to withdraw into a meditative state. This highly evocative texture, recalling tranquil images of Japanese gardens at the foot of misty mountains, is reflected in the ensuing second movement, where chiming and cuckoo motives reinforces the bird and garden metaphors from the first movement.

The energetic third movement, in which the flute again appears on edge, seemed to be heading towards a different conclusion, as an impressive climax, built up by musical ideas frothing up in the orchestra, overwhelms the flute. However, rather than riding the waves, the music meanders further before petering out with an almost apologetic, yet assured, unobtrusiveness. Watkins’s Flute Concerto is a vivid work of intense profundity and musical freshness.

Vividness and freshness are just two qualities the orchestra, under Harding, brought out in Mahler’s score too. The whole orchestra combined to produce an astonishingly colourful sound, positively teeming with life in the dew-filled morning mist and cuckoo calls of the first movement, brimming over with excitement. There was a definite sense of enjoyment emanating from the orchestra’s assured alpine romp, which teetered into a delightfully teasing waltz in the second movement’s trio. Things sobered up somewhat in the Frère Jacques funeral march of the third movement, for which double bass leader Joel Quarrington set a serious tone which never succumbed to parody. The finale found Mahler at his most breathtakingly bombastic, overwhelming the audience by sheer weight of sound as the brass instruments dominate. I find this aspect of Mahler’s music rather exhausting, so only a completely compelling performance could have had me – as this one did – revelling in this immensity, urging it onwards, practically laughing out loud at the amazing effect this music was having on me. It was an exhilarating end to a quite brilliant concert.