THE music-making at Trinity (now Trinity Laban) College of Music, now based in Greenwich, has always figured among some of the finest in London. Under capable leadership and with first-rate teaching on, not least, its conducting and composition courses, Trinity often offsets staple diet with rare repertoire, and usually emerges triumphant.

Karlheinz Stockhausen, doyen of the 1960s avant-garde, whose landmark (1968) work Stimmung has just been performed by Trinity Laban, under Gregory Rose's leadership, at the Queen Elizabeth Hall, on the South Bank, was once anathema to anyone inclined to the more traditional end of the classical-music market. It is strange how different things can seem in retrospect. In this version, a magnificent vocal sextet, Stimmung can now be seen more as a forerunner to the music of Arvo Pärt - and a mysterious after-echo of the Greek chorus - than as an apex of ugly noises.

It is a masterpiece of delicacy, subtlety, and challenging musical elegance, as Rose's 1980s Hyperion recording with his group Singcircle (CDA 66115) demonstrated. Now Trinity Laban students have won their spurs with a fine rendering that in many ways matches the 1980s rendering, when the singers were indeed arranged "in a circle", each voice feeding off the others, often in a kind of instinctive osmosis. The work was actually written for students at the Muzikhochschule in Cologne.

The mesmeric, almost minimalist chanting, the aleatoric sighs and yelps, brass-like honkings and glissandi have long become a part of commonplace musical language, even if the ambiguous Stimmung (it can mean tuning, pitch, temper, feeling, mood, ambience) still sounds cutting-edge, partly because the atmospheric "overtone-singing", which Stockhausen - a Roman Catholic by upbringing -derived from Tibetan monks, feels utterly fresh and undated.

The text, in which many words are repeated like a mantra, pays tribute to deities of the world: the Hebrew Yahweh, Allah, Vishnu, Quetzalcoatl (Aztec), the Egyptian Osiris, and so on. The very naming of each becomes a kind of spiritually passionate, cosmic, syncretic invocation of a universal deity, akin to certain later works by John Tavener.

There are some - once controversially - erotic texts (addressed to his future wife) by the composer himself, some of them slowly spoken, which were intended to be along the lines of the Oriental fusion of the erotic and the divine in, say, the great Sufi poets, or the Song of Solomon.

What one admires about these young singers is their sophistication, precision, ability to fall from a massive sforzando to the tiniest of pianissimi - here quadruple piano - and to sustain rhythms even where lesser voices might come badly unstuck. Stimmung contains many common chords. Making those interesting requires stamina, perfect pitching, and big talent. Trinity has all these in abundance.