Igbo, a language of the Kwa branch of the Niger-Congo family, is spoken by about 15 million people in southeastern Nigeria. Its phonology, morphology and syntax have been widely studied, especially with reference to the intricate patterning of lexical tone. This paper is a preliminary study of the phonetic interpretation of Igbo tone. We use an experimental method first applied to English ([3, 4]), in which a speaker varies pitch range orthogonally with variation in tonal material, and we compare the success of different models in characterizing the interaction of tone identity, phrasal position, tone sequence, and pitch range in determining patterns of measured F0 values.