Though an analysis of the radif as a whole reveals much structural consistency, modal logic is still often taken by musicians and music scholars as a foundation of the system. Indeed, scholars classify gusheh that do not conform to the modal parameters of their given dastgah as modulatory figures, thus giving their noncompliance with the modal parameters of the dastgah a modal function in the course of performance. Yet tension remains between the specificity and idiosyncrasy of melodic material within the seven dastgah and the framework of abstract modality that many musicians and scholars like to use to describe the dastgah.
The development of more composition within the radif-dastgah tradition facilitated greater exploration and development of dastgah modality. The reng and the chahar mezrab became models for composition, focusing notions of composition on instrumental forms. A new instrumental form also appeared in the course of dastgah performance called pish-daramad (pīshdarāmad). Though the pish-daramad is listed in the earliest available charts of the gusheh, musicians of the twentieth century regarded it as a separate phenomenon that was added later, distinct from the other instrumental gusheh. Like the reng and chahar mezrab, the pish-daramad has both a specific rhythmic count and a specific place in the order of performance. It was played by all instruments in the performance in a moderate 2/4. It was designed to precede the daramad as a kind of overture, thus the name pish-daramad (before-daramad). The expanding application of composition within a largely improvisational performance practice allowed greater exploration of the concept of dastgah modality, as musicians made decisions about the modal parameters they would use to compose a piece that was not defined by any particular sequencing of gusheh or poetic structure.
In addition to the instrumental compositions, the insertion of metered songs (taṣnīf) into larger dastgah performances gave musicians and poets alike an opportunity to create contemporary compositions. While the vocal gusheh consistently used classical Persian poetry, tasnif could use newly composed melody and text. The tasnif would ultimately become the largest realm of composition. Its placement in the performance of a dastgah presented an opening for changes to performance structure. Tasnif provided moments of metered singing in the middle of a dastgah performance, in the midst of long sections of vocal improvisation. Any and all instruments could also perform tasnif in full heterophony with the voice, as meter allowed for full melodic coordination of an instrumental ensemble with the singer.
In the procedure-focused performance model of the radif-dastgah tradition, a musician or group of musicians would choose a dastgah or avaz-dastgah, and then use the gusheh of that dastgah or avaz-dastgah to give a performance that was typically divided between portions that were improvisation upon the vocalstyle gusheh and portions that consisted of verbatim reiteration of compositions and instrumental forms of gusheh. There are many potential ways of executing a performance within this format, but the instrumental musically metered sections would typically mark moments of transition: the beginning of the performance, the end, and transitions between the longer, unmetered improvised sections in the middle of a performance.
The customary long-form performance common in the early to mid-twentieth century often began with a pish-daramad. After the pish-daramad, the daramad introduced improvisation on gusheh that highlighted the basic modality of the dastgah. The daramad was punctuated toward the end by the rhythmic chahar mezrab. As the performance went on after the daramad, additional sections of improvisation on new sets of vocal-style gusheh moved further and further away from the initial modality of the dastgah while also moving higher and higher in terms of register. Forud figures appeared at various points, reiterating the original pitch set emphasized in the daramad. A tasnif composition demarcated the end of an improvisatory section. As tasnif compositions grew in number and popularity, multiple sections of improvisation could be delineated by tasnif, not just forud. Performing the reng marked the end of the entire performance of a dastgah.
The term avaz came to refer to the long sections of improvisation on the vocalstyle gusheh, and these sections were initially the essential core of performance. The dastgah served as a predetermined plan of which melodic materials would be used and in what order, but the concept of avaz governed the actual improvisational performance. Avaz was the procedural execution of the plan outlined for a dastgah in practice.
Radif and Its Significance in Modern Persian Music
