The tombak , tonbak (تنبک) or zarb (ضرب) is an Iranian goblet drum. It is considered the principal percussion instrument of Persian music. The tombak is normally positioned diagonally across the torso, while the player uses one or more fingers and/or the palm(s) of the hand(s) on the drumhead, often (for a ringing timbre) near the drumhead's edge. Sometimes, tombak players wear metal finger rings for an extra-percussive "click" on the drum's shell. Tombak virtuosi often perform solos lasting ten minutes or more.