Thanks so much for the recommendations! I will be making use of these shortly, I hope; thank you especially for the paper.
As far as the term "avant-garde" goes, I confess I use the term at best loosely, and at worst incorrectly. I [ab]use it in the same sense aesthetician Nick Zangwill used in his paper
The Unimportance of the Avant-Garde (warning: links to *.doc file): "I use ‘avant garde’ in a broad sense so that it includes the artistic movements of the 1920s and 1930s that thought of themselves under that label. Thus avant garde art includes the ready-mades of the early Twentieth Century; but I also use it to include pop art and conceptual art of the 1960 and onwards." By this citation, I hope only to demonstrate that my error, if not justifiable, is at least not mine alone!