How do you analyze a two tone system – when both tones are high?

Muka Qiang has two phonological tones. Contrary to typological expectations of a two-tone system, both are types of high tone: non-high syllables are toneless. The first type of tone is a high word tone that aligns with the left edge of the word and spreads rightward, linking to as many as four syllables; lexical prosodic domains longer than four syllables have not been observed. The other tone is an accentual high tone that occurs on up to one syllable per word, and does not spread. The accentual tone attracts stress, but not all stressed syllables have this tone. High word tone does not spread past the accentual tone. Verbs appear to have the same tonal patterns as nouns; nevertheless, the research focused on nouns, so that the same elicitation frame could be used throughout the elicitation. Acoustic data from multiple speakers have been gathered, in order to substantiate the claims made in the paper. The paper is based in part on field data gathered in August, 2006.