This book investigates the topics of tone, vowel harmony, and metrical structure, with special reference to Kera, a Chadic language spoken in Chad and Cameroon. Kera is a tone language where a change in the pitch of the word can make a difference to its meaning. Drawing on a decade of experience living and working with the Kera, Mary D. Pearce looks at both the phonetics and phonology to examine how tone interacts with the vowel quality and rhythm of the language. The implications arising from this research are relevant for phonologists and Africanists far beyond the boundaries of Chad and should be useful to anyone working on languages with interesting tonal and rhythmic properties.