What the Philharmonia started as a bonus for those attending their mainstream concerts later in the evening has now acquired a life of its own. Admission to the Music of Today concerts is now free to anyone who wants to turn up, and the Queen Elizabeth Hall was very decently full for the first of this season's programmes, devoted to the music of Wolfgang Rihm. Most of those who came along, I suspect, were not planning to stay on for the full orchestra's concert of Weber, Mozart and Beethoven, conducted by Christoph von Dohnanyi.

Rihm continues to compose so prolifically that any London concert of his music is likely to contain at least one UK premiere. There were two of them here, ensemble pieces framing the relatively familiar Chiffre I, the hyperactive starting point in 1983 for a whole series of works under the same name. The octet Kalt, from 1991, represents Rihm at his most enigmatic: what begins as a series of fragile whisperings from the strings suddenly turns to a battle for supremacy between oboe and cor anglais, both obsessing ever more frantically on a single repeated note; when that tussle has run out of energy, the bass drum takes over with an unpredictable series of beats, and the piece ends. It's thin on material. Almost like a series of musical doodles, but disquietingly powerful all the same.

In Frage, written six years ago, is more coherent, continuous and openly expressive. It centres on a elegiac melody that wouldn't be out of place in a late Mahler symphony, and which weaves its way through the textures, unforgiving and fiercely direct, and creating its own musical grammar as it goes. With André de Ridder conducting, the performances had the edge of immediacy Rihm's music needs; Sarah Nicolls was the extrovert solo pianist in Chiffre I.