An analysis and definition of "?q?? " and "Vazn" (meter) with an observation of the treatises of the 3rd to 9th AH centuries

From the 3th to the 9th AH centuries (Lunar), Muslim scientists endeavored to write numerous treatises on music. Almost in all treatises the science of ?q?' allocated a section to itself and in rare cases,included the whole treatise. The definition of "?q??"has been introduced in almost all the treatises mentioned above, contrary to the definition of "vazn" which has been introduced only in one treatise. A close observation on the definitions of the term ?q?', proves that in some cases the definitions are different but related; they have general and exclusive relation. Here is the most general and comprehensive definition of "?q?? ": "maintaining the length of the time units of naqar?t(naqreh-ha)".Naqreh is the Persian word for naqrat and naqrat means naqr one time and according to the definition presented by F?r?b?, naqr is striking the narrow extremity of a hard object onto another hard object, so this contact seems to be limited to one point. The narrowness of the object which strikes and fewness of its components is relative; therefore he continued that the thinner the object, the better it satisfies the meaning of the word naqr. Avicenna generalizes the term "naqreh" as to hitting one's sound generative limbs when speaking or singing such as lips, tongue, etc. Avicenna mentions two kinds of naqreh : a naqreh which produces a tone and a naqreh which produces a letter. The definition of naqreh given by Abd al-q?der suggests that there are 3 types of naqreh: it is of practitioners' opinion that naqreh is either to vocalize a letter, or to strike a string, to clap or more generally to strike any object onto another; first ,the naqreh which produces a letter, second, the naqreh which produces a tone, third, the naqreh which neither produces a letter nor produces a tone, such as striking a daf( a percussion instrument). J?m? calls the naqar?t producing tones, naqar?t-i lahn?yyah( melodic naqar?t) and the naqar?t being produced by hands or other instruments which are played accompanying the metric melody, naqar?t-i ghayr-i lahn?yyah( non-melodic naqar?t). Owbah? calls the naqar?t producing tones which are considered as the beginning of time units of tones, naqar?t-i mub?d?yah and the naqar?t being used together with tones(such as clapping or striking a daf(a percussion instrument) by hand ) and are specified to metric melody, naqar?t-i muq?renah. By choosing this definition of the term ?q??: " maintaining the length of the time units of naqar?t" as the basis definition, every other definition of ?q?? is in a manner more exclusive than this one. These definitions indicate either "melodic ?q?? " (which can be considered as maintaining the length of the time unit of melodic naqar?t) (such as F?r?b??s definition), "Regular ?q?? "(which can be considered as maintaining the length of the time unit of the naqar?t that has equal cycles) (such as Saf?-al-d?n's), or "Regular Melodic ?q?? "(which can be considered as maintaining the length of the time unit of melodic naqar?t that has equal cycles) (such as J?m??s definition).