The oud is a pear-shaped, short-necked stringed instrument used widely in Arabic, Turkish, and Persian music. It is the direct ancestor of the European lute. Unlike a guitar or lute, the oud is fretless, which allows musicians to play the microtones (quarter tones) that are essential to the 'Maqam' (the system of melodic modes in Arabic music). It typically has 11 strings, arranged in five pairs with one single bass string. The soundboard is usually made of spruce and features intricate carved 'rosettes' over the sound holes. Traditionally, the oud was played with a plectrum made from an eagle's feather, though modern players use plastic picks. The instrument's deep, resonant, and woody tone has made it the 'king' of Arabic instruments for centuries, serving as both a solo virtuoso instrument and a centerpiece for orchestral ensembles.