Van Keulen, LPO, Jurowski, Royal Festival Hall

Readers might be wondering how often the spectre of Trump is destined to loom in reviews.

Well, Vladimir Jurowski's daring (and undersold) second concert with the London Philharmonic Orchestra under the loose aegis of the Belief and Beyond Belief series teemed with timely, if disconcerting, heavy grotesquerie, above all in the 85-year-old Vaughan Williams's Ninth and last Symphony. In a week beyond belief in a sense that the Southbank didn't intend, the monster in the Oval Office was bound to be conjured in the mind's eye.

There were only glimmers of transcendence in a programme which put frozen mourning and depression highest on the list. Not a great deal of contrast, then, but plenty of connections in the keening stepwise intervals of Georgian old master Giya Kancheli's Mourned by the Wind "for orchestra and solo viola" (note the order), Martinů's Memorial to the Nazi-massacred inhabitants of Czech Lidice and the Vaughan Williams symphony, the first movement of which starts and ends with the very same low-register heavings as the Martinů.

Kancheli's elegiac Liturgy, as it is subtitled, inhabits a world all its own, a static one in which insistent threnody, launched on the cusp of audibility by the wonderful Isabelle van Keulen (pictured right by Marco Borggreve), meets very selective orchestral thrashes but goes its hallowed way with minute adjustments of instrumental colour which always hold the ear; not minimalism by any means, but certainly minimalistic. From pianist Catherine Edwards's shocking initial gesture via a late requiem of trombones to the final halo of strings, this was a masterclass in perfectly-placed sonorities, van Keulen and Jurowski between them judging the intensity of the silences to equally powerful effect. The 81-year-old composer was enthusiastically received; hard by then to grudge the concert's late start as Georgians and other guests drifted into the hall at the beginning.

Even though Kancheli has many more things to say after the mid-point – eerie waltz and shadowy chromatic figures from the viola included – it could have stopped there. Martinů in his public memorial knows how to say so much in a mere eight minutes. Certainly this isn't as mobile or as chameleonic a work as any of the six symphonic masterpieces – I'm still reeling from last Saturday's searing performance of the Fantaisies Symphoniques under Jakub Hrůša in Bamberg – but it carves its arch effectively in marble, and Jurowski, sometimes criticised for objective distancing, urged the unstinting intensity of the strings as they briefly soar in the native idiom Martinů never forgot during his painful exile.

Jurowski (pictured below by Chris Christodoulou at last year's Proms) could also have applied his usual spring-heeled precision to Vaughan Williams's riveting swansong. But he chose instead to underline the heavy-heartedness broken up only by lyric laments in the first movement – clarinets and harp, later solo violin (guest leader Kevin Lin, soulful) – and the savage parades of the symphony's weird and frightening interior. The three saxophones were paramount here, reminding us how Vaughan Williams had much earlier used the timbre to make a smarmy horror of Job's comforters in his Biblical ballet. Niall Keatley's flugelhorn only briefly suggested air from another planet.

This is certainly not territory totally unknown to earlier VW works; the composer was savage in the 1930s and '40s, too. I'll never forget a Royal Philharmonic concert including the furious Fourth Symphony advertised as "Green and Pleasant Land" – and the Ninth treads even more desolate landscapes (Salisbury Plain and Stonehenge were suggested in the composer's soon-to-be-suppressed initial programme of the closing stages in Hardy's Tess of the D'Urbervilles).

Only passing moments of human compassion lighten the canvas. But decidedly the mood is more depressed and barely relieved by an irony that verges on the extremes of Shostakovich's Eighth Symphony, or by a more open-hearted song which is absolutely the composer's own personal domain. Jurowski kept the discipline in the embattled unisons, but didn't try to lift the gloom. Not even the parting of the clouds announced by swirls of harps before the calm final bars reveals anything truly comforting. Strange, unlike anything else: a unique voice in music, realised with perfect mastery.

• Read more classical music reviews on theartsdesk