Sepideh Shafiei

Sepideh Shafiei, S. Hakam

Unaccompanied vocalists usually change the tuning unintentionally and end up with a higher or lower pitch than the starting point during a long performance. This phenomenon is called pitch drift, which is dependent on various elements, such as the skill of the performer, and the length and difficulty of the performance. In this paper, we propose a computational method for measuring pitch drift in the course of an unaccompanied vocal performance, using pitch histogram and DBSCAN clustering.

Sepideh Shafiei

Since the early twentieth century, intervals and tuning systems have been subjects of discussion among Iranian musicians and scholars. The process of Westernization and then a cultural back to roots movement are among the reasons that motivated debates about the appropriate tuning in this musical culture. In this paper, we first review the historical context of the intervals in Perso-Arabic musical culture since Farabi in the tenth century. Then we focus on the audio histogram of the vocal performance of each piece in the repertoire (radif) of Karimi, one of the masters of the art, and use Dynamic Time Warping for alignment of pitch and MIDI notes. We collected the intervals used in the performance of each piece (gushe) in the repertoire and then analyzed the results. Unlike the traditional methods of measuring the frequency of each note played on the tar (an Iranian lute) practiced by contemporary music scholars, our computational method is independent of a given instrument and can be executed on any performance with minimum effort.