The Sruti-peti or Sruti box is a small box which works on a system of bellows and is used to provide the drone in a concert or for practice. The tones normally heard are the Tonic and the Dominant. A melodic instrument that does not fall under the three general categories of stringed, wind and bellowed instruments is the JaItarangam. This consists of a set of eighteen porcelain cups of varying sizes. The cups are arranged in a semi-circle before the performer, in decreasing order of size, starting with the largest cup to the performer's left and ending with the smallest to his right.
Water is poured into the cups and the pitch is changed by adjusting the volume of water in the cup.
The bigger cups produce a deep, bass sound and the smaller ones produce high-pitched tones. Thus, the cups are arranged in an increasing order of pitch from left to right. The cups are struck with two thin bamboo sticks. All compositions of medium and fast tempi can be played effectively on this instrument. It is a solo instrument which is usually accompanied by the mridangam.