The second version of the Arab theory is that Amir Khusraw which used to be hourglass shaped .
Amir Khusraw is a musician patronized by Sultan Alauddin Khalji invented the tabla when he cut an Awaj drum .
The second version of the Arab theory is that Amir Khusraw , a musician patronized by Sultan Alauddin Khalji invented the tabla when he cut an Awaj drum , which used to be hourglass shaped .