Alex has rightly characterized Berry's work as positivist, and outlined Berry's "wholistic approach" within that domain. But I would challenge Alex's view that "Structural Functions in Music must be recognized as belong to an age passed . . . where the
pursuit of "the essence" of a piece of music was possible and profitable" I know that I am old-fashioned and all, but I think that "a desire to `know' in a fully complete way" has been at the root of philosophical, scientific, and aesthetic inquiry for as long as knowledge has been around. If Structural Functions is unsuccessful in giving answers to all the questions one might pose, that does not mean that it is irrelevant. The pursuit of knowledge and wisdom is by no means derailed by post-positivist approaches. On the contary, such approaches simply underline our desire to know from as many vantage points as possible. The limits of positivism, particularly in the arts, are better defined through non-positivist approaches.
I think that Berry would have hoped that Structural Functions would have been read as liberating analysts from the partisan approaches of the previous generation, the kind of thing that Perle and Schenker may be faulted for, for example. Berry, after all, tries to reconstruct analysis from first principles that he would see as outside any particular tradition.