|Abstract:||The vowel harmony systems of the Bantu A.60 languages of Cameroon provide an extraordinary wealth of uncommon properties not yet exploited by linguistic theory. In this seminar I will focus on one variant of the Yambasa cluster, Kalong, whose long-distance, counterfeeding ATR, front, and round harmonies argue strongly for a representational, underspecified approach to surface opacity and neutral vowel phenomena. I will demonstrate how a bottom-up or 'system-driven' approach leads to an insightful analysis of some rather interesting vowel harmony facts, which bear on several issues, including: (i)the nature (e.g. 'abstractness') of underlying representations; (ii) the analysis of vowels systems in general, e.g. simpler /i, u, a/ or /i, e, u, o, a/ inventories. Concerning this latter issue, I conclude with a brief discussion of Punu, another Bantu language, spoken in Gabon.