Last Wednesday, the London Philharmonic Orchestra and Vladimir Jurowski presented a compellingly propulsive concert at the Southbank Centre. Pairing Mahler’s epic Sixth Symphony with the première of James MacMillan’s newly commissioned Viola Concerto, the orchestra was at the top of its game in both of these powerful works.

MacMillan’s Viola Concerto, with soloist Lawrence Power, was a haunting mixture of the old and the new. In the outer movements, chorales often lurked beneath the surface, but something was usually a bit off or distorted about them. The wide-ranging final movement also featured a delightfully off-key march and a hauntingly beautiful passage with solo flute evoking the Japanese bamboo flute, the shakuhachi. One of the most striking effects came shortly after, when the solo viola’s rhapsodic ornaments were echoed by two other solo violas and two solo cellos. The effect was a bit like a delay pedal, or like a pebble dropped in a pond, causing a gentle cascade of ripples. It was a touchingly intimate moment before the orchestra revved back into gear to propel the work to its energetic conclusion.

The second movement was lyrical and nostalgic, with a beautifully unfolding solo viola melody over pale chords in the strings. It was at times unabashedly Romantic, but never slipped into cliché. For my money, MacMillan could have embraced his inner Romantic even more fully. In the second movement, the soaring lyricism gave way periodically to loud, discordant orchestral interruptions. Nothing wrong with that, but this material was decidedly less convincing than what it interrupted. And the sighing glissandi in the solo viola line that at first touchingly evoked the stylings of an expressive jazz singer, were eventually over-developed into annoying and unintentionally humorous-sounding de-tuned slurps. Again, nothing wrong with this per se, but they felt out of place in the context of the rest of the movement. I wondered if the composers’ motivation was more to prove his own modernity than to follow the internal logic of the music.

That said, it was on the whole a touching and convincing work. It was also exceedingly well orchestrated, with a rich palette of orchestral colors that nonetheless always left the soloist plenty of space to sing and soar above. Lawrence Power projected ease and confidence, with a rich, gorgeous sound on the lyrical parts, and energetic precision in the virtuosic passagework. He was always clearly in command, but never ostentatiously so. The orchestra followed Power’s lead, with a richly colored and detailed performance. It was a great start for this welcome addition to the solo viola and orchestra repertoire.

After the interval, the LPO followed up with an astonishing performance of Mahler’s Sixth Symphony. With its great range of moods, extremely detailed notation, and over-the-top Romantic sensibility, Mahler’s works would seem to be an open invitation for conductors to engage in extremes of tempo variation, rubato, and nuance. What was so revelatory about conductor Vladimir Jurowski’s version of the Sixth, then, was the expressive power that can be achieved through pure rhythmic precision as well. This is not to say that Jurowski did not engage in his share of rubato, or that it was not a nuanced performance. Far from it. But in addition, the marches rolled continuously forward. The waltzes danced and lilted. Yes, there is expressive power in the shapes of melodies, the details of articulation, the colors of the harmonies. But, as this performance revealed, there is also expressive power simply in the rhythmic relentlessness of a march or a waltz. What at first might have seemed like a glossing over of details was in fact a decision to let the expressive power of these rhythmic forms speak for themselves.

The result was revelatory. Never before had the colossal formal structures of the outer movements made so much sense or seemed so inevitable. The fourth movement especially was like an enormous, wheezing machine, sometimes chugging along at full throttle, sometimes grinding to a halt, then building up steam again. What had always struck me as an amazing, but mystifying, juxtaposition of numerous different ideas suddenly became one continuous, coherent thread. It was one of those rare performances that actually changes the way you think about and hear a piece of standard repertoire.

The orchestra was right there with Jurowski all the way through. More than almost any other Mahler work, the Sixth is a truly symphonic conception; although there are solos and small chamber groupings from time to time, the large mixed orchestral sound predominates. The orchestra achieved a wonderful blend, balance, and richness of sound. The woodwinds especially played with a great range of colors and characters, the brass were powerful without being over-bearing, and the percussion section was extremely precise. All in all, it was a captivating evening that I will be thinking about for some time to come.