Formal structural units in Dastgah shur of Ali Akbar Shahnazi’s Advanced Radif/ types of sentences

abstract
It is very important to investigate and recognize the spatial-sound, time-weight and formal infrastructures in the Dastgah system of Iranian classical music. The topic discussed in this research is the investigation of formal infrastructures in the Dastgah Shur from the of Ali Akbar Shahnazi’s Advanced Radif, which is considered one of the important repertoires of this field. The form can be examined in three structural levels "macro", "middle" and "small", this research is especially done at the small level. "Tone", "figure", "motif", "phrase", "sentence" are structural units that make up the smallest level in a piece or "Gushe", in which the composer or musician can present his musical ideas. Citing reliable sources, the author describes each of these units and redefines them in a phenomenological way based on the level of the Advanced Radif and gives examples of the mentioned repertoire for each. Among all the units, some have high frequency and appear many times in the structure of the Gushe, these units are considered to be the characteristics of this Dastgah and especially the special style of phrasing of Ali Akbar Shahnazi, whose introduction is one of the other goals of this research. "Independent phrases", "type two-phrase sentences", "type three-phrase sentences", "sentences with more than three phrases", "expanding sentences", "compound sentences", "modulating sentences and phrases" and "Phrase groups" are formal units extracted in this field of research, among which "independent phrases" have the most frequency, which shows Ali Akbar Shahnazi's special phrasing style. pieces and formal units can be classified into three groups: "Based on the motif ", "intermediate" and "free form". 14 of the 22 pieces of the Dastgah Shur use motifs in their structure, and among the formal units, "motif sentences" have the most frequency. From the result of these two, it can be concluded that the structure of the Dastgah Shur of Andvanded Radif passion and especially Ali Akbar Shahnazi's phrasing is "Based on the motif". Another aspect of this research is to investigate the role of notes on the formation and degree of finality of formal units. In the modal regions of the Dastgah Shur, the "Shahed" note is considered strong and "stable" in terms of closing power, and other degrees are considered "unstable" and weak.

Keywords: Iranian classical music, Radif, Dastgah Shur, form, sentence.