What distinguishes the tasnif from other Persian vocal music, the singing found in the radif (avaz), is that while the avaz is unmeasured and improvisatory, the tasnif has a definite meter. It is also composed, although not necessarily notated. Furthermore, the poetry used for each type of singing is different. For the avaz, classical poetry is generally used. The tasnif, on the other hand, occasionally quotes single lines from classical sources but depends heavily on contemporary poetry or poetry composed within the last century. For this reason E. G. Browne defined the tasnif as a "topical ballad."17 He traces its origin back to pre-Islamic Persia when in the courts of the Sassanian kings, famous minstrels such as Barbad sang of the events of the day. Another tasnif singer whose skill as a harpist is legendary is Rudaki, who lived early in the tenth century. Verses of Rudaki have survived, the most famous being those of the song he performed before the Samanid Prince to induce him to return to his native city of Bokhara.
In the first decade of the twentieth century, a great number of topical satirical ballads were Written, the majority of them in disguise—that is, with seemingly innocuous verses which acquired political or even revolutionary overtones only when sung. The greatest tasnif writers of this period were Aref and Sheyda. Considering its long history, its importance as a nrajor form in Iranian music today, and its extensive development during the twentieth century when the influence of Western music is so strong, the tasnif in itself could be the subject of an extensive treatise. Its discussion here, however, will be limited to its form as it relates to the radif and to a brief discussion of performance practices.
Early Speculations of Rhythm in Classic Persian Music
