Can improvised music be great with lots of players?
Personally, I find lots of people playing at the same time is constricting. With a big lineup I often find myself thinking "I'd better leave some space..." so am not really focussed on what I am doing and hence it doesn't bring out what I consider to be my best playing. It can be very hard to hear what people are doing and hence to truly respond or interact with it. This maybe the same for the audience: Too much is overwhelming, if we give them too many sounds at once then they are not able to discern or make sense of them all simultaneously? Naturally I've heard others say this can be the attraction of large pieces; 'tuning in' to just some of the sounds, consequently everyone hearing the piece differently at every listen. Being overwhelmed and overtaken by the sounds.
Clearly this ties in directly with what we think and feel music is and what it should do. Does it need to offer a clear distinguishable arrangement/melody/rhythm etc? Would it be better if it did? I try to set different combinations up in Cold Bath Street. Dense moments packed with sounds, sparse moments with very little happening, traditional sections of arrangement with instruments fulfilling their traditional roles.
So how many is too many? Certainly with a rock set up - a sonically big distorted guitar, bass, drums and keyboard four or five players works well. This gives enough to respond to and interact with without getting into the overly dense sonic space where clear rhythm is lost and the sonic potential energy of the constituent sounds is diminished. Indeed if we wanted more room we might go down to three players? If the sounds are sonically smaller and the improvisers are leaving a lot of gaps then the group could be bigger. With care given to the choice of instruments this could lead to a piece with a more varied timbre?
As with so many things it is personal taste. I like enough room for someone in the group to change what they are doing and for the other members to be able to hear what they've done and go with that. The music in this way is 'light on its feet' - it doesn't get bogged down or dirge-like... however I know lots of people who like nothing better than a good sonic dirge with no room or anything being clearly discernible!... Go figure!