The oud is a pear-shaped stringed instrument commonly used in North African and Middle Eastern music. The modern oud and the European lute both descend from a common ancestor via diverging paths. The oud is easily distinguished by its lack of frets and smaller neck. The instrument appears in ancient Egypt art from the 18th dynasty onwards in long and short-neck varieties. Today’s oud is totally different from the old prototypes, however. Egyptian ouds tend to be very ornate and highly decorated.
The origin of the name oud (and its etymological cousin, lute) for the musical instrument is uncertain, but the Arabic al-?ud refers literally to a thin piece of wood similar to the shape of a straw, and may refer to the wooden plectrum traditionally used for playing the oud, or to the wooden soundboard that distinguished it from similar instruments with skin-faced bodies. It can also be an Arabic borrowing from the Persian name rud, which meant string, stringed instrument, or lute.
Lack of frets: The oud, unlike many other plucked stringed instruments, does not have a fretted neck. This allows the player to be more expressive by using slides and vibrato. This development is relatively recent, as ouds still had frets in AD 1100, and they gradually lost them by AD 1300, mirroring the general development of Arabic music which abandoned harmony in favor of melismatics (the use of multiple tones during one syllable).
Strings: With some exceptions, the modern oud has eleven strings. Ten of these strings are paired together in courses of two. The eleventh, lowest string remains single. The ancient oud had only four courses.
Peg box: The pegbox of the oud is bent back at a 45-90° angle from the neck of the instrument. This provides the necessary tension that prevents the pegs from slipping. The tension of the strings helps to hold what would otherwise be a weak joint together. The nut is held in place by the string tension, rather than being glued. The pegs do not slip if tapered accurately; if they do, chalk is used to make them stick more, and soap to enable them to slip more.
Body: The oud’s body has a staved, bowl-like back resembling the outside of half a watermelon, unlike the flat back of a guitar. This bowl allows the oud to resonate and have a particular tone quality. The shape is structurally very strong and stable enabling it to be very thin. Although made of dense hardwood good instruments are not heavy.
Sound-holes: The oud generally has one to three sound-holes, which may be either oval or circular, and often are decorated with a carved bone or wooden rosette.
Construction of the oud is similar to that of the lute. The back of the instrument is made of thin wood staves glued together on edge. Alternating staves (or ribs) of light and dark wood are often used. The instrument usually has an odd number of staves. This means the back will have a center stave rather than a center seam. Contrasting trim pieces are often used between staves. Patterns and wood species used generally vary from maker to maker. In better instruments the wood is always cut on the quarter from a dense hardwood.
The top of the oud is generally made of two matching pieces of thin spruce glued together on edge. Transverse braces, also of spruce, are glued to the underside of the top. The neck is generally made of a single piece of wood and is usually veneered in a striped pattern similar to that of the back.