The qānūn is a trapezoidal shaped plucked zither used widely in the Middle East and especially in the Arab world and Turkey. The word qānūn translates as (the law). The reason behind this appellation is that the qānūn is the only musical instrument in the oriental takht (traditional Arabic ensemble) that can play all the notes of Arabic scales on open strings. Secondly, the rest of the ensemble depends on the qānūn for setting the pitch and tuning. It is not only regarded as one of the central instruments in the traditional Arabic ensemble, but also the equivalent of the piano according to texts in early 20th century Arab music theory. Across the Arab world the instrument is almost exclusively played by men, except for rare exceptions where the instrument is played by women.

Although it is constructed of wood, a characteristic feature is that the bridge is supported on pillars that rest upon tables of skin. It has 78 strings, the majority of nylon or gut, organized in courses of three to each pitch (the bass strings are brass wound and in courses of two). They are plucked with plectrums made out of turtle shell or plastic, inserted in a ring on each index finger.

Until the modern period, the qānūn was overshadowed by other instruments as it was difficult for the performer to cope with the microtonal adjustments required to change to another mode (maqām): the strings had to be stopped with the fingernail. This problem was overcome by the introduction of a number of levers beneath each string: raising them causes the vibrating length of the string to shorten, so that the pitch rises. The result is much greater precision and flexibility, although the performer is faced with the difficulty of having to think ahead and make adjustments to the levers with one hand while continuing to play with the other.

Thanks to its versatile nature, its ability to produce a myriad of textures, and its wide range (three and a half octaves), the qānūn has become increasingly important not just as part of an ensemble accompanying a singer, its traditional role, but also as a solo instrument in its own right. As Maya Youssef’s recording demonstrates, this has been accompanied by the creation of a new solo recital repertoire and, to go with it, an expanded and more virtuosic technique including, for example, the use of the other fingers to produce arpeggios