I'm not sure how useful it would be about music in theme parks, but The Global Theme Park Industry by Salvador Anton Clave is usually decent for any theme park-related stuff.
"Whole New Worlds": Music and the Disney Theme Park Experience by Charles Carson also looks like a very good read for music's role in theme parks.
Ethnomusicology Forum, 2004, Vol.13(2), pp.228-235
In this paper, I explore some of the ways in which music operates in the Disney theme park experience.
In the context of Walt Disney World, my belief is that music functions in at least three
specific capacities: 1) music links current Disney experiences to (often romanticized)
experiences of the past through nostalgia; 2) music defines the boundaries which separate
‘‘same’’ from ‘‘other’’ in terms of both geography and, ultimately, identity; 3) and music
serves as an index for the ‘‘Disney Experience’’ in general; an experience which itself is
built upon a commixture of the aforementioned modes of identity and nostalgia.
In the same journal, the very next article is called "Circumnavigation with a Difference? Music, Representation and the Disney Experience: It's a Small, Small World" by Laudan Nooshin. P236-251
This article explores the relationships of power embedded within the Small World ride and addresses a number of questions relating to the politics of cultural representation and specifically to the role of music in the ride
That's all I could find with a quick search really, but hope this helps you (if you didn't find these articles already!). I'd actually be surprised if there's anything but Disney-related articles really.
