The earliest Arab Oud musician was possibly Eben Sareeg. In the past, Arab composers wrote exclusively for Oud. It is a solo instrument used also for Taqasim (improvisations) accompanied by song. The Oud sound box is pear shaped, and it has a relatively short handle and no frets. The precise shape and dimensions differ throughout the Arab world, as do the number of strings - up to six and even seven. .

Since the 9th century the musical tradition of the Mediterranean Sea was based in great part on the Oud.

The heart of Oud music are the Makams. Makams are also playable on other instruments, but for Arab music, Makams are executed on the Oud. Makams are roughly equivalent to Indian Ragas or to Western "keys," but they are more complex than "keys" and unlike Ragas, they do not have any allegorical significance. The Makam  (Turkish makam, plural makamlar; Arabic maqam, plural maqamat) are scales or 'composition rules'.   The makam names designate an important note in the scale (i.e. Turkish Cargah, Arabic Chahargah: fourth position), or a city (i.e. Esfahan, it is sometimes spelled as Isfahan), a landscape (i.e. Turkish Hicaz, Arabic Hijazi), a person (i.e. Kurdi) or a poetic abstraction (i.e. Suzidil: heart glimmer).

Based on the use of untempered intervals (with as many as 53 microtones amplifying the western octave), a given makam follows a particular scale and a set of associated musical practices. Each makam joins a tetrachord (Turkish dortlu), and a pentachord (Turkish besli). Certain rules/characteristics of a makam may include the entry tone (Turkish giris, Arabic mabda), the final tone (Turkish karar, Arabic qarar) which may or may not be the same tone as the entry tone, the leading tone (Turkish yeden), dominant (Turkish guclu) and tonic (Turkish durak), as well as stressed secondary tonal centers. The seyir (path, way) (Arabic zahir) of a makam is determined by the direction of the melody, which may be either ascending (Turkish cikici) or descending (Turkish inici) or a combination of the two (Turkish inici-cikici). Range (makam may be extended above and below the octave without repeating), modulation, temperament, melody types, and cadential endings (i.e. suspended cadences) may also determine a makam's make-up. Compound makamlar exist which combine elements from two makamlar. Thousands of makamlar have been theoretically conceived though only a few hundred have been used. Of these, about one hundred have been fully developed into musical settings.

References

 Kurt Reinhard: The New Grove: Dictionary of Music and Musicians. vol. 19. ed. London: Macmillan, 1980

Josef Pacholczyk: The New Grove: Dictionary of Music and Musicians. vol. 1. ed. London: Macmillan, 1980

Karl Signell: Makam: Modern Practice in Turkish Art Music. New York: DaCapo Press, 1985

Walter Feldman: Music of the Ottoman Court. Berlin: GAM- Media GmbH, 1996

More Musical Instruments of the Middle East