A shruti box (or sruti box) is a small wooden instrument that traditionally works on a system of bellows. It is similar to a harmonium and is used to provide a drone in a practice session or concert of Indian classical music.[1] It is used as an accompaniment to other instruments and notably the flute. Use of the shruti box has widened with the cross-cultural influences of world music and new age music to provide a drone for many other instruments as well as vocalists.