In the years before the first world war, Schoenberg was closely connected to the Blaue Reiter artists. Hearing his Second String Quartet in 1908 had set Kandinsky and Franz Marc on the path to abstraction, and three years later when they published their Blaue Reiter Almanac, Schoenberg contributed an essay, some of his own paintings and a specially composed piece, Herzgewächse, a setting of a Maeterlinck text that is one of his masterpieces.

Nothing in music sums up the expressionist ethos more perfectly, yet because of the inhuman soprano writing and the esoteric instrumentation for harmonium, harp and celeste, performances of Herzgewächse are rare. But in this concert, planned to complement Tate Modern's Kandinsky exhibition, Eileen Hulse took on the solo part, high Fs and all, while Richard Bernas conducted the chiming, wheezing instrumental trio to conjure the intensely rarefied sound world. It's all over in less than five minutes: the soprano spirals ever higher, drawing the instruments up with her until the music evaporates into the ether.

After Herzgewächse Schoenberg began work on perhaps his greatest achievement, the melodrama Pierrot Lunaire, and that work followed here too, in a staging by Mike Ashman that evoked the original 1912 presentation. The instrumentalists were hidden behind a screen while the reciter, Sally Burgess, was white-faced and dressed in a black clown's costume. Burgess commands this work majestically, making its Sprechgesang delivery seem the most natural thing in the world, and perfectly balancing its blend of horror, humour and hysterics. Admittedly, it has its historical precursors - one of them, a gothic-horror melodrama by Liszt, Der Traurige Moönch, was included in this concert, superbly presented by Richard Angas. But in a performance as fine as this one, Pierrot Lunaire seems unique, defying classification and imitation.