The theoretical attempts of the early Arabic-Islamic writers on music were laid down in books on nagham ‘notes
’, on īqā’ ‘musical metrics
’, and on ta’līf ‘composition
’.
Books on nagham were devoted to describing the basic octave and the then current scales. This emerges from the earliest extant treatise on the subject, which was written by Ibn al-Munajjim (d. 300/912). Here, the notes are identified by letters in their numerical value (for instance, first letter alifalif...