Another fine season for the London Symphony Orchestra looks inevitable after the brilliantly played Mahler 6 they brought to the Barbican on Wednesday night. With the assured Thomas Dausgaard leading the way in this furious, huge march, the band amply showed its Mahler chops with some scintillating orchestral sounds.

While the piece is often referred to as the "Tragic" symphony – a name Mahler toyed with but decided against – much of the time it seems angrier than tragic, right from its fierce, militant opening, played with stern precision by the LSO. Even the rhapsodic second theme, intended to represent Mahler's wife Alma, is marked ff, and – especially if played as committedly as it was here – sounds only as full-blooded as it does unhinged. But all unfolds with a grim, concise inevitability: despite the symphony's considerable length, this is Mahler at his least sprawling. His eyes were perhaps fixed firmly on that incredible ending, right from the start.

There are, of course, endless things that a conductor might do with a Mahler symphony. But while interpretations vary, so do orchestras, and Thomas Dausgaard seemed content to let the LSO emerge as the true stars this evening, conducting a conventionally-minded account which thrilled primarily because of the sheer brilliance of the orchestral performance. Most remarkable, despite some chilling tutti playing, was a single, sudden chord for woodwinds in the slow movement: an uncannily beautiful sound, perfectly in tune and yet filled somehow with all the rusticity Mahler was surely after. The Scherzo, placed third here, lacked a little bite, but the focus of the finale was a thing of wonder. Despite this movement's great length and apparently chaotic structure, it flowed, thrilled, enthralled.

Dausgaard may have let the LSO's sound speak for itself, but that's not to say he didn't make an impression too: he cuts an extremely dynamic figure on the podium, sweeping and Romantic in his gestures. He may not appear to have the subtlety or mystique of some conductors, but the results he achieved here in this Mahler 6 are impossible to argue with.

The first half of the concert seemed very long ago by the time the final hammer-stroke fell, but earlier on there had also been some Richard Strauss: his Burleske, an early work for orchestra and piano, with Barry Douglas as soloist. It's a virtuosic piece in every sense, which gives the impression of the young composer basking in his almost unholy gift for orchestral composition, and expecting the orchestra and soloist to likewise relish the chance to show off. A demonic drive propels this waltz-time work with its initial theme presented strikingly on timpani. Though the beginning stages were a little too stable here, lacking a sense of adventure, it had all come into focus by the ridiculous, cheeky closing gesture – again starring the timpanist Nigel Thomas in some remarkably melodic playing. Douglas had clearly mastered the enormous technical challenges of this work, though his performance was efficient rather than indulgent or showy – not quite right for a piece so light in effect.

Though both this evening's pieces end rather grimly in the minor, the effects could hardly have been more different – this juxtaposition highlighted the huge differences between these two contemporaneous composers. For Strauss, the sinister minor ending masks a deep-set humour; for Mahler, it's more or less the end of the world. And the LSO made it sound like that, as well. Thankfully, there's time for a few more concerts yet.

Strauss and Mahler, at Barbican Centre: HallPaul Kilbey reviews Thomas Dausgaard with the LSO and Barry Douglas in Strauss and Mahler 6.4