The santoor is an Indo-Persian trapezoid-shaped hammered dulcimer or string musical instrument generally made of walnut, usually with seventy-two strings. It is the national musical instrument of Iran and a traditional instrument in Jammu and Kashmir. A primitive ancestor of this type of instrument was used in Mesopotamia (1600-911 BC) and Babylonia.
In ancient Sanskrit texts, it has been referred to as shatatantri vina (100-stringed vina). In Kashmir the santoor was used to accompany the folk music. It is played in a style of music known as the Sufiana Mausiqi where Sufi mystics used it as an accompaniment to their hymns. It is generally unsuitable for performing Indian classical music because it cannot create meends, a vital feature of classical music.. In Indian santoor playing, the specially-shaped mallets (mezrab) are lightweight and are held between the index and middle fingers. A typical santoor has two sets of bridges, providing a range of three octaves. The Indian santoor is more rectangular and can have more strings than its Persian counterpart, which generally has 72 strings. Musical instruments very similar to the santoor are traditionally used all over the world.
The trapezoid framework is generally made out of either walnut or maple wood. The top and bottom boards sometimes can be either plywood or veneer. On the top board, also known as the soundboard, wooden bridges are placed, in order to seat stretched metal strings across. The strings, grouped in units of 3 or 4, are tied on nails or pins on the left side of the instrument and are stretched over the sound board on top of the bridges to the right side. On the right side there are steel tuning pegs or tuning pins, as they are commonly known, that allows tuning each unit of strings to a desired musical note or a frequency or a pitch.
The santoor is played while sitting in an asana called ardha-padmasana position and placing it on top of the lap. While playing, the broad side is closer to the waist of the musician and the shorter side is away from the musician. It is played with a pair of light wooden mallets held with both hands. The santoor is a very delicate instrument and is very sensitive to light strokes and glides. The strokes are played always on the strings either closer to the bridges or a little away from bridges. Both styles result in different tones. Sometimes strokes by one hand can be muffled by the other hand by using the face of the palm just to create variety.