A study examined the tonal patterns in Komo, a sub-Bantu language of about 200,000 speakers in Zaire. It investigated: (1) the minimal lexical specifications necessary for Komo tones; (2) what sort of tonal alternations exist and how they may be accounted for most simply with rules; (3) how tonal phenomena interact with Komo morphology; and (4) at what level of derivation the various tone rules apply. Three strata of derivation (the two lexical strata of derivation and inflection, and a post-lexical stratum of phonological phrase formation) are used as an organizational basis for describing tonal phenomena. The resulting report gives an overview of Komo lexical tone for nouns and verbs and proceeds to analyze tone patterns in each stratum. A concluding section outlines the resulting rules. Notes on instrumental analysis of downstep and a list of abbreviations are appended, and a 23-item bibliography is included. (MSE)