Kramer's Postmodern Music Theory

Jonathan Kramer posits the idea (following Umberto Eco and Jean-François Lyotard) that postmodernism (including musical postmodernism) is less a surface style or historical period (i.e., condition) than an attitude. Kramer enumerates 16 (arguably subjective) "characteristics of postmodern music, by which I mean music that is understood in a postmodern manner, or that calls forth postmodern listening strategies, or that provides postmodern listening experiences, or that exhibits postmodern compositional practices." According to Kramer (Kramer 2002, 16–17), postmodern music:

1. is not simply a repudiation of modernism or its continuation, but has aspects of both a break and an extension
2. is, on some level and in some way, ironic
3. does not respect boundaries between sonorities and procedures of the past and of the present
4. challenges barriers between 'high' and 'low' styles
5. shows disdain for the often unquestioned value of structural unity
6. questions the mutual exclusivity of elitist and populist values
7. avoids totalizing forms (e.g., does not want entire pieces to be tonal or serial or cast in a prescribed formal mold)
8. considers music not as autonomous but as relevant to cultural, social, and political contexts
9. includes quotations of or references to music of many traditions and cultures
10. considers technology not only as a way to preserve and transmit music but also as deeply implicated in the production and essence of music
11. embraces contradictions
12. distrusts binary oppositions
13. includes fragmentations and discontinuities
14. encompasses pluralism and eclecticism
15. presents multiple meanings and multiple temporalities
16. locates meaning and even structure in listeners, more than in scores, performances, or composers

It should be noted here that Kramer is again referencing work in the Western art music tradition, and does not seem to be addressing music from the "popular" end of the spectrum; this kind of intentionality is not unheard-of in popular music, but it is quite unusual.

From Wikipedia's POSTMODERN MUSIC page.