Why is the starting assumption that tunes evolve? Not everything "evolves" as such.

Without Darwin, perhaps, there would have been none of the academic folklore or comparative musicology of the late nineteenth - early twentieth century. The concept of natural selection was an inspiration to them, even if its application to culture wasn't necessarily sound. But scholarship moved beyond those models. "Folk" aficionados of today, especially of an English leaning, might still be enamored by the Anglocentric gentleman/lady folklorists of that early era, yes. But this is hardly "ethnomusicology"—the founding of which field was in large part a statement of opposition to evolutionary models.

In that light, I'm puzzled why this is "an Ethnomusicology class" or why, by the same token, reference material by ethnomusicologists on musical change has not (evidently) been sought. (I'll say that it doesn't have to be an ethnomusicology course; it could be an English Literature course, Folkloristics, etc. - to each discipline its own methods. But to call it an ethnomusicology course sets up certain expectations.)

One will find that ethnomusicology hasn't been waiting around for people in the hard sciences to come and bring the answers to music through application of superior scientific reasoning :-) (If one doesn't see current ethnomusicologists discussing evolutionary theory, it's not because they haven't found it yet, but because they left it long in the past.) It's probably your responsibility, Pamela, to figure out WHY this is if you're presenting such a course.

Yes - What might be more interesting, assuming this is a course is the humanities, is to ask more "why?" questions. Such as my opening question: "Why the starting assumption that tunes evolve?" Most students have probably never considered how people with different worldviews—including a group of people roughly characterized as "Western atheist scientists"—think differently about how music works. I think such discussion can ultimately be more transformative for students than studying someone's theory of how tunes evolve. Indeed, there is no set canon to be imparted on "How Music Changes," so it might be better rather to explore the topic of musical change while leaving it open to different approaches—wherein evolutionary theory would be just one. I appreciate that it's your preferred way of thinking about the topic, but I don't think it's appropriate (at least not typically) for this type of humanities course (ethnomusicology particularly) to say, "OK, everybody, here's how this phenomenon [probably] works." Show different sides.

As a guide to further reading:
I'd say this topic generally ceased to be discussed in ethnomusicology by the 1960s, so look before that for literature. 1930s-50s is probably your best bet. You might see what the different approaches were as represented by European comparative musicology (Erik von Hornbostel as a representative scholar), Continental musical folklore (Bela Bartók as a representative), and post-Boas, Euro-American early ethnomusicology of the likes of George Herzog and M. Kolinski. Bruno Nettl, who was around during the founding of the Society for Ethnomusicology in the 1950s, would remember these trends and one or more of his retrospective books (_31 Issues in Ethnomusicology_ or something like that) would somewhere survey "musical change" in an accessible way. See also the entry for Ethnomusicology in the 2001 edition of the Grove Dictionary of Music and Musicians. Good luck.

Dr. Gibb Schreffler (Music Dept.)
Director of Ethnomusicology Program
Pomona College