It was Goethe ... who was responsible for the apt and often quotes remark that a string quartet is like a conversation between four intelligent individuals. Since the age of Viennese classicism the string quartet has remained the crowning glory of chamber music (if not all music). [p. 11]I have a quibble about Klüppelholz's parenthetical condition - since the age of American classicism (aka "Bebop") the quintet has remained the crowning glory of THIS MUSIC.
The glory that was that Arditti evening in Detroit's Orchestra Hall has never been - perhaps never will be - repeated. However, the economics of chamber music verses orchestral music certainly fits today's bust-economy better than yesterday's boom-economy. So perhaps chamber music - both THAT and THIS MUSIC - will, in a manner of speaking, flourish.
Try this: http://boulezian.blogspot.com/2013/10/sixtieth-birthday-concert-for-irvine.html