Shruti Box

Shruti box(sruti box), also known as sur peti is a simpler version of harmonium that works on bellows and drone system. It produces a drone-like continuous sound. The controller can adjust the pitch of the drone. Its origin is India and it is widely used in Indian classical music, sound healing, yoga-meditation, mantras, vocal cord training & exercise, and it is also used as an accompanying instruments to provide a reference point for tuning and staying in tune.