Most Americans who study music formally do so using common-practice era western tonal theory. Tonal theory is very useful in understanding the music of western Europe in the eighteenth and early nineteenth centuries, and the music derived from it. However, tonal theory is inadequate to explain the blues and other musics of the African diaspora. Given the central role of this music in both popular culture and art music, music theory classes do their students a grave disservice by not discussing its harmonic content.
The blues cannot be explained by Western tonal theory. Nevertheless, the blues emerged in western culture and is now a central pillar of it. McClary (2001) observes that while twentieth-century music has no single main stream, it does have a “mighty river” that follows a channel cut the blues:
When LeRoi Jones published his powerful book Blues People in 1963, his title referred to the African American musicians who fashioned the blues out of their particular historical conditions and experiences. Yet a music scholar of a future time might well look back on the musical landscape of the 1900 s and label us all “blues people”: those who inhabited a period dominated by blues and its countless progeny (32-33).
It no longer makes sense to think of the blues, or any other music of the African diaspora, as non-Western. Therefore, Western music theory must grow to accommodate the blues, the same way that the music itself has.