This publication is a rigorous scientific work by Mohamed Lassaad Kriaa. It is a detailed commentary of a manuscript which can be considered as a reference about the major principles - of music in the Arab-Islamic cultural space in the 13th century, entitled "Al-Risâla Al-Sharafiya fi al -nisab al-ta'lifya (Epistle on Music)"and attributed to Safi al-Din Al-Urmawi, a brilliant musician and great theorist, considered to be the founder of one of the oldest theory school related to "Arabic music ” and "the systematic school".

This publication has great importance. On the one hand, this epistle did not equal "Kitâb al-Adwar (cycles book) of Al-Urmawi in scientific studies, despite the interest of Baron Cara de Vaux, Baron D'Erlanger and of Hajj Hisham Muhammad al-Rajab. On the other hand, the elements of this work present a complete gloss, including an in-depth study as the Professor Mahmoud Guettat wrote on the preface.