The Tanpura is a four to six stringed fretless instrument made of wood, and usually combined with gourd. It provides the performing artist(s) with a tonic reference and enriches the background with its unique harmonic drone. The strings are tuned in a manner that emphasizes the tonic and the dominant notes of the raag. The bridge is slightly curved to not only provide a buzzing sound (as the strings are plucked), but also to generate various harmonics that enhance the tonal quality of the instrument. The size (gourd and neck) of the instrument may vary depending on whether the artist is an instrumentalist, male vocalist, or a female vocalist. Tanpura was most probably included as a part of a classical music ensemble since the seventeenth century.
The Tanpura player plucks the strings one at a time, in a steady, repetitive, almost orderly manner, using the index and middle fingers.
These days "electronic" tanpuras have become commonplace, since they do not require a human player, are less expensive, simpler to tune, require minimal maintenance, and are easily portable. Many Indian professional musicians (including world renowned artistes like Pandit Debu Chaudhuri and Pandit Aashish Khan) are now touring without a tanpura player and are using the Riyaz Raagini sampled electronic tanpura machine as it sounds so very realistic. However, some artists prefer a natural instrument to an electronic one when available, and sometimes combine the two types. Electronic Tanpuras are, naturally, used by many students for practice as in this way the student can practice for long periods of time as and when needed without the need for a person to sit and play tanpura for them.