In the sphere of Malay and Indonesian literature, it is only recently that students of oral narratives have paid attention to their character as oral performances, and this thesis is the first study of a West Sumatran metrical narrative to take that aspect of it into account. Versions of the story of Anggun Nan Tungga exist in manuscript and printed form, and are performed as dramas and sung narratives in two parts of West Sumatra: the coastal region of Tiku and Pariaman and the inland area around Payakumbuh. Sijobang is the sung narrative form heard in the Payakumbuh area. It is performed on festive occasions by paid story-tellers called tukang sijobang, who learn the story mainly from oral sources. The story is usually sung in part, not in full. However, a recital of the complete story by one tukang sijobang was recorded, and a full summary, about 40,000 words in length, is given in chapter II. The plot differs somewhat from one story-teller to another, the greatest differences being in the least-performed parts. Chapter III contains transcriptions, about 1200 lines in length, of two sung performances of sijobang, with translations and notes. This is preceded by a discussion of the various tunes and their uses; metre; phonetic differences between the Payakumbuh dialect and standard Minangkabau; literary features such as formulae, themes, parallelism and repetition; and the forms and uses of pantun in sijobang. Chapter IV examines the ways in which a tukang sijobang's performance of a scene varies from one occasion to another. An outline comparison of three pairs of scenes shows that a scene remains largely stable in structure (i.e. number and order of speeches and sections) and in content from one performance to another. A more detailed analysis of two pairs of transscriptions (about 360 lines) shows that speeches, like scenes, are basically stable in structure and content, but that details of expression are fluid. The evidence also suggests that, compared with a novice, an experienced tukang sijobang relies less on the repetition of stock phrases and more on substitution within formulaic patterns. Being in some respects exploratory rather than exhaustive, the thesis points the way to a number of potentially fruitful fields for further research.