Rebab

The rebab (Arabic الرباب or رباب - "a bowed (instrument)") , also rebap, rabab, rebeb, rababah, or al-rababa) is a type of string instrument so named no later than the 8th century and spread via Islamic trading routes over much of North Africa, the Middle East, parts of Europe, and the Far East. The bowed variety often has a spike at the bottom to rest on the ground, and is thus called a spike fiddle in certain areas, but there exist plucked versions like the kabuli rebab (sometimes referred to as the robab or rubab)
The rebab usually consists of a small, usually rounded body, the front of which is covered in a membrane such as parchment or sheepskin and has a long neck attached. There is a long thin neck with a pegbox at the end and there are one, two or three strings. There is no fingerboard. The instrument is held upright, either resting on the lap or on the floor. The bow is usually more curved than that of the violin.

The rebab, though valued for its voice-like tone, has a very limited range (little over an octave), and was gradually replaced throughout much of the Arab world by the violin and kemenche. It is related to the Iraqi instrument the Joza, which has four strings.

The introduction of the rebab into Western Europe has possibly coincided with the conquest of Spain by the Moors, in the Iberian Peninsula. There is however evidence of the existence of bowed instruments in the 9th century also in Eastern Europe: the Persian geographer of the 9th century Ibn Khurradadhbih cited the bowed Byzantine lira (or lūrā) as typical bowed instrument of the Byzantines and equivalent to the Arab rabāb.

Construction 

The rebab is used in a wide variety of musical ensembles and genres, corresponding with its wide distribution, and is built and played somewhat differently in different areas. In Southeast Asia, the rebab is a large instrument with a range similar to the viola da gamba, whereas versions of the instrument further west tend to be smaller and higher-pitched. The body varies from being ornately carved, as in Java, to simpler models such as the 2-string Egyptian "fiddle of the Nile" may have a body made of half a coconut shell. The more sophisticated versions have a metal soundbox and the front may be half-covered with beaten copper, and half with cowskin.

Arabia, Persia and the Ottomans 

The rebab was heavily used, and continues to be used, in Persian music. There is also a bowed instrument in Persian music named Kamanche which has similar shape and structure. The Rebab is also played in other countries such as India, most likely tracing its origin to Greater Iran because of its use in the Sassanid court. It was adopted as a key instrument in Arab classical music and in Morocco a tradition of Arabo-Andalusian music has been kept alive by descendants of Muslims who left Spain as refugees following the Reconquista. The rebab became a favourite instrument in the tea houses of the Ottoman (Turkish) Empire.

Indonesia and Malaysia
In the Indonesian gamelan the rebab is an essential elaborating instrument, ornamenting the basic melody. It does not have to conform exactly to the scale of the other gamelan instruments and can be played in relatively free time, finishing its phrases after the beat of the gong ageng (the big gong that "rules" the ensemble). The rebab also frequently plays the buka when it is part of the ensemble.

In the eastern Malaysian states of Kelantan and Terengganu, the Rebab is used in a healing ritual called "Main Peteri". The musician healer is sometimes taken to hospitals in cases where doctors are unable to heal ailing patients. 

 

(source : en.wikipedia.org)