Indian musical instruments are remarkable for their beauty and variety of forms which, as seen in the paintings at Ajanta, have remained largely unchanged in the last 2000 years.  Among all the classical musical instruments, the tanpura, or tambura as it is called in south India, is special as it crosses the divide between Hindustani and Carnatic music, between dhrupad and khayal, vocal and instrumental, and classical and folk music. This drone instrument is considered the foundatio