The yazh is an ancient Dravidian instrument, equivalent to the Harp. One of the musical instruments mentioned in quite a few literary masterpieces in Tamil, the yazh was considered to be the sweetest of instruments. It was also one of the main accompanying instruments to vocal music, apart from being played as the primary instrument.
The yazh was an open-stringed polyphonous instrument (Polyphonic meaning: Music with two or more independent melodic parts sounded together), with a wooden boat-shaped skin-covered resonator and an ebony stem. It was tuned by either pegs or rings of gut moved up and down the string. The yazh highly resembles the Veena, among the Indian Instruments, in structure. It is designed in such a way that the stem of the main body of the instrument tapers to the resemble the head of the weird animal 'Yali' (vyala in Sanskrit). Hence the name 'yazhi' or 'yahzh'. Depending on variations in designs, the instrument took different names such as 'mayuri yazh' (mayuri meaning peacock), 'vil yazh' (Vil Yazh - it means bow string. It was essentially a bow with strings of different lengths: vil meaning bow), etc.
Based on the technical differences, there are several variations of the yazh. The Peri Yazh was supposed to have 21 strings; the Makara Yazh with 17 strings; whereas the Sakota Yazh had 16 strings; Senkotti Yazh had 7 strings and so on.
The yazh has been mentioned in quite a few ancient Literature works and can also be seen in Temple sculptures. To mention a few: The Tirupalli yezhuchi of Tiruvembavai ("Innisai veenaiyar yazhinar orupal"), Tiruneelkanta yazhpanar is believed to have been an exponent in playing the instrument. "kuzhalinithu yaazhinithu enba tham makkal mazhalai chol kelaathavar" is one of the 1330 'kural's of Tiruvalluvar written about 2000 years ago.
An associate of Kovalan (the hero) in 'Silappadhigaaram' was not only a musician and a talented singer, but could also play a difficult type of Yazh called Sakota Yazh. Senkotti Yazh is again mentioned in 'Silappadhigaaram'. Seeri Yazh, Maruththuva Yazh and Adi Yazh, Matchya Yazh, Maruthuva yazh are other varieties which are mentioned in ancient Tamil Literature. Sculptural depictions of the yazh can be seen in the temple in Tirumayam (near Pudukkottai), Amaravathi and Khajuraho, to mention a few.
The yazh is an unfretted instrument and is played with both hands. It was tuned to a particular scale. Other scales were played on it by the shift of the tonic note or by retuning the particular strings. Thus the yazh may be said to be the precursor of the later Eka Raga Mela Veena. The yazh had many limitations. Only straight notes could be played on this instrument. There were no facilities for playing the Gamakas or Quarter-tones. Further, it took a long time to tune the instrument. Thus the fretted Veena emerged without the above limitations. When the fretted veena emerged, the yazh slowly receded to the background. The fretted Veena enabled any raga to be played with ease and without loss of time involved in tuning. With the emergence of the concept of Aadhara Shadja, the playing of the new scales by the shift of the tonic note became an anachronism and a thing of the past.