Literally, jaltarang means "waves in water". The Jaltarang or Jalatharangam is an Indian melodic percussion instrument. It consists of a set of ceramic or metal bowls tuned with water. The bowls are played by striking the edge with beaters, one in each hand.  Earlier, since China clay bowls were not available, artists used to play this instrument with metal bowls. Each bowl can be tuned to the desired frequency by varying the quantity of water in it. These bowls are placed in a semi-circle arrangement around the artist and played. The Jaltarang has a pleasant characteristic tone similar to the Feng Shui wind chimes. The player can produce on it, classical Indian Ragas and light melodies as well. 

Inspired by Jaltarang, glass music became popular in sixteenth century Europe using glasses in place of cups. Another variation of the Jaltarang is found in Jaisalmer district in Rajasthan in India, where a single metal plate, called the thali, filled with water, is used as an accompaniment by applying strokes to produce different tones and rhythms. It is called Jaltaal.

Credits : wikipedia, indianraga.wordpress.com