The Bulbul Tarang (बुलबुल तरंग) literally "waves of nightingales", alternately Indian Banjo) is a string instrument from India.
Tuned in this manner, the instrument is uni-tonic, or not used to modulate to different keys because the fine melismatic music of India is more concerned with expressing subtle, microtonal pitch increments in a music-theoretic system radically different from Western, predominantly harmonic music; so that modulation to different keys is not considered so important.
The melody strings may be tuned to different pitches if desired, however, rendering it multi-tonic, but more difficult to play.
Similar to the Autoharp, a chord can be selected when a key is depressed, and the strings are often bowed or strummed with a pick.
In the Maldives it is known as a kottafoshi, and as medolin (pronounced "mendolin" after the mandolin) in the Fijian Indian diaspora.