The tambura, tanpura, or tambora is a long-necked plucked lute

Lute

Lute can refer generally to any plucked string instrument with a neck and a deep round back, or more specifically to an instrument from the family of European lutes....

 (a stringed instrument found in different forms and in many places). The body shape of the tambura somewhat resembles that of the sitar

Sitar

The 'Tablaman' is a plucked stringed instrument predominantly used in Hindustani classical music, where it has been ubiquitous since the Middle Ages...

, but it has no frets – only the open strings are played to accompany other musicians. It has four or five (rarely six) wire strings, which are plucked one after another in a regular pattern to create a harmonic resonance on the basic note (bourdon or drone

Drone (music)

In music, a drone is a harmonic or monophonic effect or accompaniment where a note or chord is continuously sounded throughout most or all of a piece. The word drone is also used to refer to any part of a musical instrument that is just used to produce such an effect.-A musical effect:A drone...

 function).

Tamburas come in different sizes and pitches: larger "males", smaller "females" for vocalists, and a yet smaller version is used for accompanying sitar or sarod, called tamburi or tanpuri. Male vocalists pitch their tonic note (Sa) to about C#; female singers usually a fifth higher. The male instrument has an open string length of approximately one metre, the female is three-fourths of the male. The standard tuning

Musical tuning

In music, there are two common meanings for tuning:* Tuning practice, the act of tuning an instrument or voice.* Tuning systems, the various systems of pitches used to tune an instrument, and their theoretical bases.-Tuning practice:...

 is 5-8-8-1 (sol do' do' do) or, in Indian sargam, PA-sa-sa-SA. For ragas that omit the fifth, the first string is tuned down to the natural fourth: 4-8-8-1 or Ma-sa-sa-Sa. Some ragas require a less common tuning with shuddh NI (one semitone below octave sa), NI-sa-sa-SA. With a five-string instrument, the seventh or NI (natural minor or major 7th) is added: PA-NI-sa-sa-SA (5-7-8-8-1 )or MA-NI-sa-sa-SA (4-7-8-8-1).

The name tanapura is probably derived from tana

Taan (music)

Taan is a virtuoso technique used in the vocal performance of a raga in Hindustani classical music. It involves the singing of very rapid melodic passages using vowels, often the long "a" as in the word "far", and it targets at improvising and to expand weaving together the notes in a fast tempo...

, referring to a musical phrase, and pura which means "full" or "complete". Both in its musical function and how it works, the tambura is unique in many ways. It does not partake in the melodic part of the music but it supports and sustains the melody by providing a colourful and dynamic harmonic resonance field based on one precise tone, the basic note or key-note.

The special overtone-rich sound is achieved by applying the principle of jivari

Jivari

Jivari, in Indian classical music culture and thought, refers to the overtone-rich "buzzing" sound characteristic of classical Indian string instruments such as the tanpura, sitar and veena. Jivari can refer to the acoustic phenomenon itself and to the meticulously curved bone or ivory bridges that...

, which creates a sustained "buzzing" sound in which particular harmonics will resonate with focused clarity. Jiva refers to "soul", that which gives life, implying that the tambura embodies an "animated" tone quality. The principle of jivari can be likened to the prismatic refraction of white light into the colours of the rainbow, as its acoustic twin principle at work.
To achieve this effect, the strings pass over a wide, arched bridge

Bridge (instrument)

A bridge is a device for supporting the strings on a stringed instrument and transmitting the vibration of those strings to some other structural component of the instrument in order to transfer the sound to the surrounding air.- Explanation :...

, the front of which slopes gently away from the surface of the strings. When a string is plucked, it has intermittent periodical contact with the bridge; this intermittent grazing of the string and bridge is not a static process, as the points of contact will gradually shift, being a compound function of amplitude, the curvature of the bridge, and string tension. When the string is plucked it has a large amplitude, moving up and down and contacting the bridge on the down-phase. As the energy of the string's movement gradually diminishes, the contact point of the string with the bridge slowly creeps up the slope to the top of the bridge, finally resting at the top of the bridge. Depending on scale and pitch, this can take between 3 and 10 seconds. This dynamic process can be fine-tuned using a cotton thread between string and bridge: by shifting the thread, the grazing contact is shifted to a different position on the bridge, changing the harmonic content. Every single string produces its own cascading range of harmonics and at the same time builds up a particular resonance. According to this principle tamburas are attentively tuned to achieve a particular tonal shade relative to the intonation-related qualities of the raga

Raga

A raga is one of the melodic modes used in Indian classical music.It is a series of five or more musical notes upon which a melody is made...

.

These more delicate aspects of tuning are directly related to what Indian musicians call raga svaroop, which is about how characteristic intonations strengthen the tonal impression of a particular raga. The tambura's particular setup, with its adjustable bridge, made it possible to explore a multitude of harmonic relations produced by the subtle harmonic interplay of four strings.

Tamburas are designed in three different styles:

• Miraj style: the favourite form of tanpura for Hindustani performers. It is usually between three to five feet in length, with a well-rounded resonator
  Resonator
  A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
  
   plate (tabli) and a long, hollow straight neck. The round lower chamber to which the tabli, the connecting heel-piece and the neck (dandh) are fixed is actually a selected and dried gourd
  Gourd
  A gourd is a plant of the family Cucurbitaceae. Gourd is occasionally used to describe crops like cucumbers, squash, luffas, and melons. The term 'gourd' however, can more specifically, refer to the plants of the two Cucurbitaceae genera Lagenaria and Cucurbita or also to their hollow dried out shell...
  
   (tumba). Wood used is either tun or teak, bridges are usually cut from one piece of bone.
• Tanjore style: this is a south India
  South India
  South India is the area encompassing India's states of Andhra Pradesh, Karnataka, Kerala and Tamil Nadu as well as the union territories of Lakshadweep and Pondicherry, occupying 19.31% of India's area...
  
  n style of tambura, used widely by Carnatic music
  Carnatic music
  Carnatic music is a system of music commonly associated with the southern part of the Indian subcontinent, with its area roughly confined to four modern states of India: Andhra Pradesh, Karnataka, Kerala, and Tamil Nadu...
  
   performers. It has a somewhat different shape and style of decoration from that of the Miraj, but is otherwise much the same size. Typically, no gourd is used, but the spherical part is gouged out of a solid block of wood. The neck is somewhat smaller in diameter. Jackwood is used throughout, bridges are usually cut from one piece of rosewood. Often two rosettes are drilled out and ornamented with inlaywork.
• Tamburi: small-scale instruments, used for accompanying instrumental soloists. It is two to three feet long, with a flat bed-pan type wooden body with a slightly curved tabli. It may have from four to six strings. Tamburi are tuned to the higher octave and are the preferred instruments for accompanying solo-performances by string-playing artists, as the lighter, more transparent sound does not drown out the lower register of a sitar
  Sitar
  The 'Tablaman' is a plucked stringed instrument predominantly used in Hindustani classical music, where it has been ubiquitous since the Middle Ages...
  
  , sarod
  Sarod
  The sarod is a stringed musical instrument, used mainly in Indian classical music. Along with the sitar, it is the most popular and prominent instrument in the classical music of Hindustan...
  
  , or sarangi
  Sarangi
  The Sārangī is a bowed, short-necked string instrument of India which is originated from Rajasthani folk instruments. It plays an important role in India's Hindustani classical music tradition...
  
  .