James Tenney, who died in August this year, was content to describe his output as "unpopular music". While he never quite achieved the acceptance of contemporaries such as John Cage, Philip Glass or Steve Reich, Tenney was revered among academic circles for volumes such as Meta-Hodos and its even more formidable follow-up, Meta Meta-Hodos: a Phenomenology of 20th Century Musical Materials.

There are no more dedicated exponents of Tenney's oeuvre than Zeitkratzer, a Berlin-based ensemble best known for its complete recitals of one of the most notorious pieces of unpopular music ever recorded: Lou Reed's double-album of squalling white noise, Metal Machine Music.

Zeitkratzer - whose personnel includes players from the Berlin Philharmonic and members of electronic indie bands - brought three Tenney pieces to the Huddersfield Contemporary Music festival, including the seminal Having Never Written a Note for Percussion, which has the curious distinction of being the only solo gong improvisation in the classical repertoire.

The 15-minute piece is as much a ritual as a musical performance: a lone percussionist kneels before an imposing tam-tam, and gradually agitates it to the threshold of pain, as if to inform some implacable, sonic god that dinner is ready. The impact was unfortunately diminished by an over-long first half devoted to some of John Cage's most uncompromising dirges. The interruption of a ring-tone attracted furious glances from festival patrons - yet, given Cage's interest in ambient noise and the music of chance, surely he is the one composer for whom audiences should be reminded to switch their mobile phones on?