The Persian santour is an exotic ancient instrument. In spite of its beautiful sound, the original santour has serious issues with its tuning stability and the key changing limitation. The facts mentioned above have made the composers think twice before writing for the original santour. These limitations have almost excluded the original sanour from the orchestras. 

For the first time in the Persian music history, Mohssen Behrad and Kourosh Zolani invented a new santour, Santour-7-Dastgah, which has addressed the two main constraints of the original santour. This new invention has given this exotic instrument a new life in the orchestras and a second chance among the composers and the players.

Original Santour

The Persian Santour is a stringed musical instrument with 72 strings stretched over a trapezoidal box. The Santour is an instrument played by means of two hammers striking the strings.  The Persian Santour is a three-octave diatonic instrument, which is the original form of the hammered dulcimer.

The seventy-two strings are arranged in eighteen quadruple sets.  An adjustable wooden bridge upholds each group of four strings. The four strings over a bridge are tuned to the same pitch. There are nine bridges in a row on each side of the trapezoidal box. The bass strings, which cross over the right bridges are usually made from bronze. The strings over the middle bridges are steel. The resonance box in the traditional instrument is usually made of hard wood, for instance walnut. There are several sound posts inside the box, which connect the table of the instrument to its back. The arrangement of the sound posts plays an important role in the sound quality of the instrument. Typically, there are two small rosettes on the top panel.

Not being able to change the key on a live stage is one of the most known limitations of the original santour. In the original santour in order to play in the different keys, a santour player has to retune the instrument with the tuning pins or readjust the bridges.

Changing the key with the tuning pins cannot be done in a few seconds. So it is not possible to switch from one key to another on a live stage using the tuning pins. Plus, readjusting the bridges limits the playing range of the instrument greatly. Also, it would badly affect the sound quality of the santour.

Beside the limitation mentioned above, the original santour has tuning stability issue. The tuning pins in the original Persian santour are not reliable. So the instrument gets out of tune easily.  

Santour 7 Dastgah

In a santour-7-Dastgah the two main constraints of the original santour have been addressed.

First, in this new instrument, it is possible to change the key on a live stage in few seconds. In a Santour-7-Dastgah the strings lengths are adjustable by means of an added mechanical system to the right and left sides of the trapezoidal box. When the length of the strings is changed, it will vibrate with a different frequency therefore the pitch will be different.
Second, a Santour-7-Dastgah has no tuning pins. This instrument has a totally new and innovative tuning system using specific designed metal bolts and nuts instead of the ancient tuning-pin-in-wood system. Therefore, the tuning in a santour-7-dastgah is very stable. To tune the instrument the musician would use a special supplied wrench, which fits on the tuning nuts. 

This new Santour has patent protection in many countries including Iran, USA, Canada and Europe.