pronunciation: TAAN-puraa ("u" as "u" in "put").
A stringed instrument with four (sometimes five or six) strings, strummed endlessly in the background as a drone. Three strings are tuned to the tonic and the other or others to the dominant or subdominant and/or another note of the Raga being presented at the time.
A rich, resonant and mellow toned Tanpura is a very sought-after instrument by artistes. Indian musicians and music students, as well as lay persons, enjoy the soothing and constantly strummed sound of this noble instrument: its effect is mesmerising and evocative of the primal sound -- the Pranava or "AUM" of Indian philosophy (which finds reflection, though in a somewhat diluted manner, in the Islamic "Ameen" and the Christian "Amen").
It is considered an honour for music students and junior artistes to be allowed to strum the Tanpura with a senior artiste during a concert. During vocal concerts, sometimes the main artiste may, at his/her discretion, permit the Tanpura strummer to lend a bit of vocal support or accompaniment at intervals: this is a good way for the junior artiste to be "broken into" concert performance as a soloist in the fulness of time.
See the pictures page on this site for more details about this ubiquitous instrument that is the backbone of any Indian art music concert or training session. Click on the picture thumbnail to read some more material about the Tanpura.