What is a vichitra veena?

The vichitra veena is a fretless slide instrument of Hindustani music: a broad horizontal beam, the dand, about 3 feet long and 6 inches wide. A large resonating gourd is fixed beneath each end. The player sets the pitch by moving a glass ball, the batta, along the main strings and strikes them with two mizrab plectra. It traditionally accompanied or followed dhrupad singing.