The book of the Honoured Art Worker of Azerbaijan Master of Art Zemfira Safarova "Safiaddin Urmavi" is devoted to the great scientist-musician of the Middle Ages of the East (ÕIII ñ.) Safiaddin Abdul Momin Ibn Yusif Ibn Fakhir al Urmavi (1217 - 1294). In 1994 700 years passed since his death. The founder of the famous in the Near and Middle East "Systematic school" Safiaddin Urmavi was an outstanding composer, master calligrapher, virtuoso performer in ud, creater of new musical instruments "Mugni" and "Nuzkha" too. Scientific heritage of Safiaddin Urmavi has been studied in this book. Íå is an author of two fundamental treatises on music " Kitab al advar" ("À book on circles", that's to say, mugham cicles) and "Sharafiyya" ("Sharafiyya treatise about composition or about relations in music"). Both treatises have been written in the Arabic language. Copies of these manuscripts of treatises are kept in libraries and book funds of different cities of the world - New York, Paris, London, Berlin, Istanbul, Tehran, Cairo, Vienna, Rome, Saint-Petersburg, and etc.

For the first time Urmavi's treatises were fully translated from Arabic into Azerbaijanian and studied on these manuscripts. ("Kitab al-advar" - Istanbul, Nuri Osmaniye, # 3653, 3654, "Sharafiyya" - Istanbul, Nuri Osmaniye, # 3133, 3648).

The book consists of à foreword written bó professor À.Tagizade, introduction, four chapters and epilogue.

The period of S.Urmavi and his life, the facts of his birth in Urmiye (South Azerbaijan) are considered in the first chapter. Then comes à survey of S.Urmavi's scientific heritage. Here are given location and press - marks of copies of treatises, analyzed the article of English scientist Í.G. Farmer about S.Urmavi, written on the third volume of "Arabic music" by French scientist Â.R.d'Årlàngår.

Detailed analysis of all 15 chapters of the treatise is given in the chapter "Tretise" "Kitab al - advar" bó Safiaddin Urmavi". There are given schemes, circles, tables which are revealed and interpreted by the author of the book.

The sound (nagame) and its physical and musical features, rules of division of strings, seventeen - grade scale of the scientist, intervals and their correlations, reasons of dissonance, correlation of tetrachords and pentachords, mugham cicles, rules of rendering on two - stringed instruments, ud, its sound - row and rendering of mughams in it, well - known and popular mugams and their names, parallels in mugams and transposition of mugams, unusual tuning of ud, rhythm, emotional influence of mugams and beginning of musical practice are the main problems put forward by S.Urmavi in the treatise "Kitab àl - advar" and considered in this chapter by the author of the book. In the 15-th chapter of the work Z.Safarova gives the interpretation of Western as well as Eastern scientists of four melodies of S.Urmavi noted by means of the system abjad by Í.G. Farmer, Â.R. d'Erlanger, Ar-Rajab, al-Bakri, À.Badalbayli, I.R. Rajabov and proposes her own interpretation.

It is noted that the role of theoretical achievements of S.Urmavi are significant today firstly in regulation of sound system, sound ñîmpleõ of music in the East. His seventeen - grade scale united in itself piphagoric and natural pitcher on the basis of which he put forward 12 keys and 6 avazes, compass of which did not exceed octave.

In one of copies of the manuscript "Kitab al-advar" S.Urmavi gives the information about Azerbaijan rubabist Mamed Shah who invented the rhythm "Chahar - zarb".

The third chapter of the book is called "The treatise of Safiaddin Urmavi "Sharafiyya" and is devoted to the analysis of this treatise written in 1270-es in Tabriz. The treatise was devoted to favourite student of the scientist Sharafaddin. "Sharafiyya" consists of five chapters where S.Urmavi puts forward his conception about harmony, euphony in music, theory of correlation, about relativity and demonstrates it in integral sound system, then in correlation of intervals, in circles, mode cycles, in strings of ud and composition composed in this instrument. And in all these parts S.Urmavi 's theoretical computation, ideas are new, original. We don' t meet them in the works of previous authors. The following scientists tried to continue them.

In the conclusion the author says that in Azerbaijan as well as in all musical world the valuable scientific heritage of Safiaddin Urmavi has been published only partially and that's why has not been thoroughly investigated. As it is noted in the research, many scientists of the East and West have written commentaries to Urmavi's treatises. It is of great importance to publish these works for further study of creative activity of the scientist.

Considerable place is given to Urmavi's text in the work. It makes the reader acquainted with the scientist's style, with logic of his thought.

Scientific - theoretical heritage and humanistic aesthetics of Safiaddin Urmavi has played à great role in the development of musical - theoretical thought in the Near and Middle East. It has played à great role in the development of Azerbaijan music science, in the creation of original treatise "Principles of Azerbaijan folk music" of the classic of Azerbaijan music Uzeyir Hajibeyov.