Of the "come one, come all" variety there's the audience-inclusive Spontaneous Music Orchestra (rather than the Ensemble), which mudd mentioned above. Listening to these it's clear that, just as much as the much-feared blow-out (people playing too many different things at once), there's a dreadful tendency for everyone to start playing the
same thing: drones (or "sustained pieces," as John Stevens calls them); the directions being for everyone to sustain a note for as long as possible, pause for breath, then continue with the same or another note. There's two pieces of this sort, one instrumental and one vocal, on
Mouthpiece, a collection of recordings from 1973 by unspecified numbers (probably between twenty and thirty). I suppose they bear a passing resemblance to Ligeti's pile-ups of dense clusters, especially the vocal/choral piece, but like with drone music generally, the effect really is quite dull, like you're having a feeling of transcendental, pseudo-religious awe forced on you. The other more worthwhile recordings each have a concept: "In Relation to Silence" asks the players to continually relate what they're doing to silence, presumably to avoid the kind of self-indulgent blow-out everyone's worried about; "One-Two" starts out with a chant of those words, with the players asked to play a single note on either beat, so that on each one lands a different combination of sonorities. The steady, mechanical beat really makes it sound like a Braxton composition, but with the forward-moving lines replaced with repeating, slightly shifting sonorities. By far the most enjoyable recording (at least in part) is the title piece, in which the large group is asked to start with non-vocal mouth sounds, spits, breaths, and gurgles, then to move at some point to pitched notes (where it stars to sound like the bizarre howling from the last recorded moments of the Jim Jones massacre), then at last to instruments, where the dreaded blow-out erupts and the whole thing collapses. Then it's definitely time to skip ahead to the strange ending, a great eruption of hoots, provocative claps, "shhh"s, cheers and coughing.
There's a better piece on the other SMO recording,
For You to Share: a "click" piece, where everyone is asked to make that sound exclusively on whatever they have handy. But, again, there's no shortage of sustained, droning pieces on that one either. I think Cardew's
The Great Learning has far more enjoyable pieces of this type; one asking massed voices to compete with roaring drums, with written directions providing the performers with some idea of how and when to change what they're doing, when to recite certain spoken phrases, etc.
As far as I'm concerned, I don't think there's much doubt that Simon Fell is the person producing the most enjoyable and exciting music in the area of large groups at the moment, for composition-improvisations like Composition no. 30 (
http://perso.orange.fr/brucesfingers/catalogue/bf27.htm), no. 62 (
http://perso.orange.fr/brucesfingers/catalogue/bf57.htm) and
Kaleidozyklen (
http://perso.orange.fr/brucesfingers/catalogue/bf46.htm), which has Fell hoping to invigorate a large group of classical music students. Other great music of this sort has come from Chris Burn's ensemble, particularly on the 1991 recording
The Place, for nine players (Burn, Jim Denley, Phil Durrant, John Butcher, John Russell, Marcio Mattos, Matt Hutchinson, Steve Wishart and Evan Parker); a mixture of compositions by Burn, Butcher, a graphic score by Keith Rowe and one entirely free piece. The reduced, microscopic style I think keeps the music away from an inarticulate pile-up; instead, it's teeming with tiny gestures and detailed fragments. As Rainey mentioned above, I don't think it's necessarily true that with more than five players (in this case it's nine) a flimsy compositional scheme is required to prevent the music becoming (somehow automatically) sloppy and chaotic. Sensitive musicians are perfectly capable of playing free pieces in large groups without having "their balls on show as soon as possible," as Derek Bailey would say.
On the more recent improv front, The MIMEO & Tilbury works especially well, I think, because of its opposition of forces. But what do people make of Phosphor (that's Burkhard Beins, Alessandro Bosetti, Axel D?rner, Robin Hayward, Annette Krebs, Andrea Neumann, Michael Renkel and Ignaz Schick)? A lot of the comments I've read about it seem to be of the "it's good, but they're better in smaller formations" variety.