The frets

It is difficult to attribute a precise date to the first appearance of frets on the tube-zither but the oldest sculpted reliefs are from around the 8th century A.D.
Several types of vina existed already during this period but all these instruments were devoid of frets.
Medieval treatises from the 11th and 12th centuries describe fretted vina, called kinnari-vina, which can be differentiated into several categories, according to their size and the number of strings. The frets, about the size of the little finger, were often made from vulture bone, iron or even bronze. These frets, numbering 13 or 14 on a kinnari-vina, were glued to the tube with a mixture of wax and ashes of cloth. Their position, which dictates a specific pitch, is also explained in detail for each of the different categories.