6.Conclusion: Unity through diversity.
There is a commonly held view, particularly among those concerned primarily with European musical traditions, that the American experimental movement developed accidentally, in isolation, and in a naive and undisciplined way. It further considers the composers associated with experimentalism as amiable eccentrics, whose works are far less interesting than the anecdotes about them. This view is clearly wrong. The composers discussed here, as representatives of experimentalism's first half-century, had a clear sense of direction both individually and collectively. Their music and ideas are rigorous and highly disciplined, and, at a purely technical level, revolve around a number of recurring preoccupations. Among these are:
1 extreme chromaticism of both melody and harmony;
2 tone-clusters and noise;
3 the use of new or unconventional instruments (both electronic and acoustic) and/or of conventional instruments in an unusual way;
4 rhythmic complexity, both simultaneous and successive; 5 implied or actual polytempo and/or polymetre;
6 implied or actual spatial separation of groups of instruments;
7 independent organization of the various parameters of a musical line or idea;
8 large-scale and/or small-scale structuring of form, using extra-musical devices and processes, including numeration;
9 graphic notation and/or semi-improvised music;
10 works which are indeterminate of their performance.
What should be clear is that these preoccupations have been shared in common not just among the composers discussed here, but also among their contemporaries and successors in the American experimental tradition (though, of course, not every composer has employed all of these traits, and other preoccupations - including those which have led to so-called minimalist music - have subsequently grown out of this initial list). p.218