A 10th-century group of Islamic encyclopedists of Ismaili tendencies centred on Basra, one of whose epistles (Rasā’il) deals with music. Unlike most other music theorists of the 10th and 11th centuries, the Ikhwān al-Safā’ were chiefly concerned with the neo-Platonic and Hermetic aspects of the Greek heritage. Their work is of some interest for its scientific aspects (in particular the theory of the spherical propagation of sound) and for its treatment of musical practice: for example, following al-Kindī, the discussion of the lute gives, in addition to a (simple Pythagorean) fretting, details of proportions and construction. But the most characteristic features of their work, again following al-Kindī, are to be found in their study of cosmology, where the notion of cosmic harmony (based on the Pythagorean concept of the primacy of number and numerical relationships) is the unifying principle in the discussion of such topics as the music of the spheres, the moral and medical effects of music, and the sets of natural phenomena (including the elements, winds, humours, colours and perfumes) to which the rhythms and the four strings of the lute could be related.
Rasā’il [The epistles] (MS, GB-Ob Hunt 296); Ger. trans. in F. Dieterici: Die Propaedeutik der Araber im zehnten Jahrhundert (Berlin, 1865/R), 100–153; Fr. trans. with commentary by A. Shiloah: ‘L’épître sur la musique des Ikhwān al-Safa’’, Revue des études islamiques, xxxii (1964), 125–62; xxxiv (1966), 159–93
EI2 (Y. Marquet)
H.G. Farmer: A History of Arabian Music (London, 1929/R)
F. Shehadi: Philosophies of Music in Medieval Islam (Leiden, 1995)
OWEN WRIGHT