Hathaani

Carnatic music lives in the slides between notes. Hathaani plays them with a single fretless finger inspired by the chitravina and a bow made of rollers that can sustain a note forever. The newest version moves across strings.

Hathaani is a robotic violinist built for Carnatic music, the classical music of South India - a music that depends on gamakas, the slides and embellishments between notes.

The first version, published at NIME 2021, plays the D string. A single finger inspired by the chitravina, a fretless Indian lute, travels along the fingerboard on a moving fingertip, so the robot can glide between pitches instead of stepping from note to note.

In place of a bow, two rollers drive the string. They save space, sound close to a conventional bow and allow things no player can do, such as a note that never has to change bow. The bow-hair tension can be adjusted for different playing techniques and styles.

In measurements and listening tests, Hathaani’s gamakas came across as realistic. Newer versions followed at HRI 2025 and ICRA 2026, where the robot moves across strings.