(d 1048). Arab theorist. A pupil of Ibn Sīnā, his one work on music, the Kitāb al-kāfī fī l-mūsīqī (‘Book of sufficiency concerning music’), is the last important surviving treatise on music before the rise of Systematist theory in the mid-13th century. In the choice and treatment of subject matter it generally follows the lines laid down by al-Fārābī and, particularly, Ibn Sīnā. It thus begins with the physics of sound, and surveys intervals, tetrachord species, octave divisions and melodic movement. The remaining subjects discussed are rhythm (treated methodically and clearly); composition (dealt with in a slightly less abstract way than was customary, with mention of a few technical devices and different categories of song); and instruments (including a classification scheme as well as the traditional lute fretting). Following al-Fārābī, Ibn Zayla also included a general classification of means of sound production, the ordering principle being the degree of approximation to the ideal of the human voice. The Kitāb al-kāfī fī l-mūsīqī also lays considerable stress on a traditional threefold division of music emphasizing the variety of responses that different kinds of music can evoke.
Kitāb al-kāfī fī l-mūsīqī [Book of sufficiency concerning music] (MS, GB-Lbl Oriental 2361); ed. Z. Yūsuf (Cairo, 1964)
A.-M. Goichon: ‘Ibn Zayla’, The Encyclopaedia of Islam, iii (Leiden and London, 2/1971), 974 only
H.G. Farmer: The Sources of Arabian Music (Bearsden, 1940, 2/1965), 42–3
OWEN WRIGHT