On the Role of the Obligatory Contour Principle in Phonological Theory

In autosegmental phonology, a sequence of adjacent identical tones can be represented (a) as a single tone mapped onto multiple vowels, (b) as a one-to-one mapping between multiple tones and vowels, or (c) as a combination of these extremes. The Obligatory Contour Principle (OCP) has been proposed as a constraint which restricts tonal representations to a one-to-many mapping between tones and vowels. It is argued here that the strongest form of the OCP is falsified by a number of languages which distinguish single vs. multiple tones associated with a sequence of vowels. The language-particular violations of the OCP constitute a strong argument for the full power of autosegmental phonology.