The appearance of this epistle on music is a significant event destined to enrich and enlighten musicologists interested in medieval Arabian music. The treatise, together with the writings of al-Kindī and Ḥunain ibn Isḥāq, marks the advent of a new trend which endowed the study of music with a scientific character. This was the result of the influence of works translated at that time from Greek into Arabic. The society or fraternity of the Brethren of Purity was a tenth-century intellectual circle active in Baghdad which worked for the dissemination of the doctrine destined to purify the soul of misconceptions and lead it to a clear view of the essence of reality.

The Brethren assigned a singular role in their doctrine to music as possessor of the concept of “harmony” in the broadest sense; they also exalted the Pythagorean idea of the science of music as the principal wisdom leading to philosophical thought.

In range, construction, purpose and the wealth of topics, Epistle 5: On Music is remarkable in its method, interweaving metaphorical ideas and practical subjects, and the many excursions into various fields of knowledge where music serves as a persuasive means of expounding significance, structure and interrelationships.

In view of its manifold topics, which require of the translator a keen linguistic command and great familiarity with a variety of fields of knowledge, the challenging and meticulous work of Owen Wright is most admirable. Recent intensified discussion of medieval Arabic scientific texts on music may give rise to cases of problematic terminology, which is sometimes fluid and ambiguous or inconsistent. In this respect my own interpretations sometimes differ from those of Wright.

In his introduction, Wright provides a commentary on major musicological topics, which occasionally go so far beyond the content of the Epistle that the treatment becomes a kind of general survey, barely connected with the Epistle itself. One such instance is the discussion of musical instruments (c. 15 pp.). Wright raises two issues: “whether we can infer the presence of a general organological classification in the epistle” and “whether we can define with any degree of precision the type to which a given name relates”. The discussion that follows draws on the general history of Arab musical instruments without much reference to the content of the epistle. Even the substantial discussion of the ʿūd cannot count as an organological description, since the ʿūd in this doctrine serves a symbolic function. The Brethren themselves declare at the beginning of their epistle that they will not concern themselves either with the questions Wright raises, or with any investigation relative to the instruments. They clearly define the objects of their study as the ṣināʿat al-ta'līf (the art of harmony in its broadest sense) and the maʿrifat al-nisab (the science of proportion which helps to define this lofty harmony, the knowledge of which presides at mastery in all the arts); they also say that they are not concerned with “the teaching of ghinā’”, meaning the practices of secular urban art music, which in a religious context designates the music condemned by the law; the term mūsīqī was essentially reserved for theoretical matters. That is why it seems to me that Wright's translation of ta'līf with “art of composition” and ṣinā ʾat al-malāhī (the instrumental art) by “construction of instruments” does not exactly correspond to the Brethren's approach.

Other instances of terminological difficulties are the pair of terms aṣwāt and naghamāt (p. 77) defining the fundamental constituents of a melody, which Wright translates as rhythms (aṣwāt) and tones (naghamāt). Yet aṣwāt (plur. of ṣawt) means voice or sound, and naghamāt (plur. of naghma) might mean in this context rhythms or beats; this ambiguous term is the subject of the following comment.

Saʿadia Gaon (882–942), the major figure in Jewish thought during the Gaonic period, included a paragraph at the end of the tenth treatise of his Kitāb al-amānāt wa'l iʿtiqādāt (Book of Beliefs and Opinions) that deals with the eight rhythmic modes in vogue and their influence on the human soul. H.G. Farmer, in Saʿadyah Gaon on the Influence of Music (London, 1943), identified this passage as being borrowed from al-Kindī's treatise al-Risāla fī ajzā' khabariyat al-mūsīqī (Treatise Imparting Concise Information on Music) which explores the eight rhythmic modes and links them to the theory of ethos. A network of correspondences combining melody, rhythm, humours and activities of the soul is based in al-Kindi on the classical ʿūd – strung with four strings – and the attached symbolism.

Al-Kindī used the terms īqāʾāt (rhythmical modes) and naqarāt for beats: for example, he writes “al-thaqīl al-awwal, it is three consecutive beats (naqarāt mutawāliyāt), then a quiescent beat, then the rhythm returns as it began”. Unlike al-Kindī, Saʿadia, who borrowed the theory, does not mention the names of the modes, and he uses alḥān for īqāʿāt and naghamāt for naqarāt. He writes: “As for the first lahn, its measure is three consecutive beats (naghamāt), and one quiescent; this mode stirs the humour of the blood and the temperament of sovereignty and dominion”.

The terminological preferences Saʿadia adopts testify to his acquaintance with a different theoretical tradition; there is for instance a similar usage in the Brethren's epistle, where, as mentioned above, they write: “Melodies, or rhythmical modes, (alḥān) consist of sounds and rhythms (aṣwāt and naghamāt)”. In a later, more extensive, definition, the Brethren refer to the measuring of rhythmical beats which, they say, can only be produced in a succession of alternate movements (ḥaraka) and quiescence (sukūn), terms already mentioned by al-Kindi and Saʿadia. The Brethren explain the nature of these terms saying, according to my translation: “The ‘movement’ is a displacement from one place to another, during a second interval of time; its opposite is the quiescence that indicates the stopping at the first place, during the second interval of time”. Wright's translation reads: “we may state that motion is the transfer of an object from its initial position to a second position at a second [moment in] time. Its antithesis is rest, which is [an object] remaining in the initial position at a second [moment in] time”. It seems to me that Wright's translation is a kind of abstraction of the terms, disconnected from the musical or rhythmical context. In search of a plausible interpretation I came to the conclusion that it is involved in the technique of the plectrum (midrāb) in the playing of the ʿūd. When a string is plucked with the plectrum, a beat and a note are produced simultaneously, i.e. as a rule they are produced together. The movement (ḥaraka) in using the plectrum refers to the fact that when a string is plucked, the player's hand has to move in order to pluck the string again, and during the interval between the two beats there is a certain silence, due to the special character of the plucked strings of the ʿūd, whose sounds disappear immediately after they are produced, bearing the character of percussion. Since the same terms ḥaraka (motion) and sukūn (quiescence) are used by the Arab grammarians and prosodists, it was easy to grasp a relationship between prosody and rhythm.

I hope that my observations on the intricate terminological ambiguities may add a ray of light to the eloquent contribution of Owen Wright.