Peter Manuel
https://currentmusicology.columbia
This article addresses certain aspects of the development and present form of flamenco harmony. In brief, it advances two hypotheses: first, that flamenco harmony is a syncretic product of Arab modal practice and European harmony, and second, that many of the most distinctive features of the harmonic system, and in particular the use of altered chords, have arisen in direct connection with idiosyncratic characteristics of the guitar. The first of these theses, although difficult to document, is hardly original, and indeed, is widely taken for granted among flamenco scholars.
Evolution and Structure in Flamenco Harmony