The Oud.
This strings instrument considered as the most important Oriental musical instrument of all time since all Arabic music composed by The Oud. 

The oud is one of the most popular instruments in Arabic music. Its name derives from the Arabic for 'a thin strip of wood', and this refers to the strips of wood used to make its rounded body.

The neck of the oud, which is short in comparison to the body, has no frets and this contributes to its unique sound. It also allows playing notes in any intonation, which makes it ideal for performing the Arabic maqam. The most common string combination is five pairs of strings tuned in unison and a single bass string, although up to thirteen strings may be found. Strings are generally made of nylon or gut, and are plucked with a plectrum known as a risha (Arabic for feather). Modern strings are made of steel wound over nylon. The instrument has a warm timbre, low tessatura, and is often intricately decorated. The oud used in the Arab world is slightly different to that found in Turkey, Armenia and Greece. Different tunings are used than its Arab counterpart. The European lute is a descendant of the oud, from which it takes its name (al-oud).