A percussion instrument in the Indian subcontinent, it is made of wood, brass, leather, cotton, parchment and metal. Though there are regional variations of the instrument across Bengal, Orissa, Assam, Himachal Pradesh and Kerala, it is often a hollowed barrel with two heads covered in skin derived synthetically or from animal hide. Normally, one of the faces of the instrument produces a deeper, lower-frequency sound, while the other produces a thinner, higher-frequency sound. The pitch of the dhol can be altered with the use of interlaced ropes and rings found around its body, that can be tightened or loosened.