If the essence of artistic collaboration is by its nature ephemeral then Gloria has had a good run for its money. It was exactly a decade ago that Neil Bartlett set up the iconoclastic grouping with colleagues Nicolas Bloomfield, Leah Hausman, and Simon Mellor dedicated to producing original music theatre. And they have certainly done that. No-one who saw A Vision of Love Revealed in Sleep, Sarrasine, A Judgement in Stone, or Night After Night, will ever forget them.

But Seven Sacraments marks - as will next month, Declan Donnellan's Much Ado About Nothing - the end of an era. Seven Sacraments is Gloria's last show and, typically, last Friday's performance in St Barthlomew's was a revisitation of a highly personal solo performance piece performed by Bartlett last summer in the Royal London Hospital in Whitechapel (and once, originally destined for Edinburgh).

Bartlett and Gloria's way has often been to expand an idea from the individual to the broader scale - not always, though laudable, for the better.

Here, though, the expansion is a triumph of reorientation, creating a child-centred oratorio that re-establishes and modernises the liturgical sacraments with utterly delightful freshness and originality. Bloomfield's music, eclectic, sonorous, perfectly illuminates the solemnity and playfulness of an occasion involving choir, orchestra, soloists, and school-children.

''Defend them,'' says Bartlett at one point with such searing gravity that anyone even thinking of doing harm to the young charges scampering over the nave would, you feel, immediately be turned to stone.

The brilliance, however, has been in offering them space to voice their own 1998 words and in so doing revitalise rites of passage in danger of losing all meaning for today's new generation.