A Sassanid era mosaic excavated at Bishapur
The chang (Persian: [tæ]) is a Persian musical instrument similar to harp. The Turkish name is çeng and the Arabic name is al-?ank (?an?). It was very popular and used widely during the times of ancient Persia, especially during the Sasanian Dynasty where it was often played in the shahs' court. It was also played until the 19th century in the Ottoman Empire but has disappeared now from the classical Ottoman music and Turkish folk music.
The chang has appeared in paintings and wall art in Persia since its introduction in about 4000 B.C. In these paintings and mosaics, the chang went from the original arched harp to an angular harp in the early 1900s B.C. with vertical or horizontal sound boxes. By the beginning of the Common Era (1 A.D.), the chang had changed shape to be less of a handheld instrument and more of a large, Hellenistic (which was gaining popularity at that time), standing harp. Sassanian courts were enamored with the more Hellenistic chang and increased its popularity, but by the end of the Sasanian period, the chang had been redesigned to be as light as possible. Becoming more elegant, the chang lost much of its rigidity and structural soundness, but gained a portability that made it the primary harp for what would soon become Iran. The chang that is used today resembles the last documented transformation.
The chang is essentially an Iranian harp, but unlike an eastern harp the strings are made of sheep guts and twisted goat hair and sometimes even nylon, this characteristic gives the chang a unique sound in which it does not have the resonance of most traditional metal strings in other harps. In medieval Azerbaijan, the chang had 18-24 strings but varies based on how far the chang dates back. In the design of some ancient changs, sheep skin or goat skin was used to amplify the sound making it sound closer to an eastern harp, but its unique sound is desirable and typically preserved. The chang is played by plucking the strings with your right hand finger nails or finger picks and using your left hand to apply pressure on the strings to execute glissandos, vibratos and other embellishments and occasionally, plucking techniques. In modern days the chang is made out of special string or the tail of a horse. The past structure of the chang was typically goat or sheep skin. The skins used on the chang also give it a different sound.
The chang was predominantly played by women during ancient times. However, the chang is being revived and is now starting to make its way back into the field of contemporary Persian music. There are records from as far back as 4000 B.C. that depict pictures of the chang being played, along with other instruments and a singer. Since the playing style of the chang does not share any similarities with other Persian instruments, it is a difficult instrument to pick up, play and master. As a result, the number of chang players is small. There are a few modern players of the chang including Mrs. Parvin Ruhi and her two daughters Zaynab Baqeri Nejad and Masome Baqeri Nejad. Today the chang is played in small ensembles, such as religious ceremonies and parties. In recent years, the Iranian scholars and instrument makers have been trying to revive the ancient chang back to its former glory.