In the 1990s Daniel Wolf talked about a "post-experimental" phase, meaning that "'experimental' refers to a type of music of a particular historical era, essentially, if not quite exclusively, the music of the fifties, sixties, and seventies stemming from Cage's 'hard' definition" (Gilmore 2014, 27). This era implies the operating and maintenance of a complex "experimental scene" that supports itself from within and that includes "the composers themselves, [and] mediating factors compris[ing] a complex network of festivals, foundations, academic institutions, venues, private patrons, performers, publishers, publicists, critics, musicologists, and so on" (ibid.). ( 5)"'Experimental' is all the interesting new music that isn't avant-garde" (Gilmore 2014, 28). [Michael Nyman's definition.] 9This typology, succinctly but rigorously proposed by Bob Gilmore, situates itself in an "experimental world," which is inspired by the thought of the sociologist Howard S. Becker (see Becker 1982), but crucially remains musically (and not sociologically) oriented. Even if limited to music from the twentieth century, it is a most useful typology both from the viewpoint of historical musicology as well as from the perspective of composers, providing a common framework of reference to diverse practices. Two complementary questions become inescapable: (1) Was there no experimentation in music before the twentieth century? and (2) Are there no political implications when one advocates and puts into action an "experimental attitude"? Or, formulated differently, Does experimental music (or experimentation in music) remain in a beautifully encapsulated limbo, independent of the world "out there," as suggested by Daniel Wolf 's definition, which seems based on an ivory-tower "experimental scene"? At the very end of his essay, Bob Gilmore (2014: 29) refers to the first question, stating, "As regards the work of older composers, I'm of the opinion that some music is inherently, not temporarily, experimental."What, then, is music that is "inherently experimental"? Reflecting on this question triggers many other related questions: Is there an experimental attitude recognisable in different times, styles, and places? Are there any detectable "experimental affinities" throughout music history? How do new artistic paths emerge through experimental performance or compositional practices? What is the character, function, and potential of experimentation in musical practice? How does experimentation shape artistic identity and expertise? These were the fundamental questions discussed at the International Orpheus Academy for Music and Theory in the