• A conch shell is called the shankh and is a drone instrument.shell image by Mirek Hejnicki from Fotolia.com
  
  Indian drone instruments unify and blend the components of Indian music by sounding a constant pitch or pitch sequence. Drones using a single note, two notes or many notes are used to produce varied effects. The tambura, or tanpura is the instrument played most in Hindustani and Carnatic music. Other drone instruments include the ottu, a south Indian drone instrument, the surpeti, the south and north Indian ektar, the dotar and the shankh. Their applications and regional associations vary.
  
  

The Tanpura or Tambura

• The three tanpura styles are the miraj, the tanjore and the tamburi. The miraj style is usually 3 to 5 feet long and is preferred by Hindustani musicians in north India. It is readily recognized by a long neck and pear-shaped resonator face. The resonator is typically made of a gourd. The tambura is a member of the lute family. The tanjore style is favored by the Carnatic musicians of southern India. The resonator is made of wood and the neck is tapered. The tamburi style is easy to carry and maintain because of its smaller size. The tanpura is prized for its rich, full-bodied sound.
  
  

The Ektar

• The ektar's simple construction consists of a gourd and bamboo. Ektar means "one string" and includes several other one-stringed instruments such as the tuntun, katho, anand lahari and gopichand. The ektar is most popular in rural regions and is associated with folk music.
  
  

The Dotar

• The dotar is a two-stringed, simple instrument that resembles the ektar. It is often used in folk music.
  
  

The Ottu

• The ottu, which is primarily used in south India, provides the drone for temple ensembles. Its four or five holes are closed with wax to bring the ottu to the appropriate pitch.
  
  

The Surpeti

• The surpeti is a small box also known as the swar pethi, sruti box or shruti box. The electronic surpeti is sometimes called an "electronic tambura." The manual surpeti is pumped with small bellows by the hand and has no keys. Carnatic musicians use the surpeti in stage performances but Hindustani musicians do not.
  
  

The Shankh

• The shankh is a simple conch shell with limited musical functions. It is presumed to announce the triumph of good over evil when it is blown. The shankh is associated with the Hindu religion.