The Structure of Middle Eastern Music
Below you will find information on the structure of music common in Middle Eastern genres, including information on sturctual elements such as Maqamat (Maqam, singular) and Ajnas (Jins, singular).
Middle Eastern music often sounds strange to Westerners, some describe it as sounding "off." What they are generally referring to is that Middle Eastern music frequently uses notes that are uncommon in Western music. Arabic Music is modal and divides equally into 24 tones (whole, half, and quarter tones) while Turkish music in practice also divides into eighth tones providing for approximately 30 Maqamat (مقامات). This focus on melody as opposed to harmony make Middle Eastern music sound strange to Westerners who are used to scales based on whole tones and harmony.
A mode is a way of ordering notes of a scale according to the intervals they form with the tonic scale. This provides a theoretical framework for the melody. The mode specifies the which notes can be used to elaborate that framework for the melody. Western musicians strive for originality and individuality in their music but much of Arabic music seeks to utilize the same melody types but rather seeks to exploit the melody in different ways to create ther music.
Traditionally each maqam had a different emotional quality associated with it. This is similar to the way certain types of Western music are described as sad, happy, or imply danger or something miraculous. The Maqamat had various emotinoal qualities in much the same way. Some Maqam (مقام), much like specific drum rhytms, are said to attract certian evil Djinn.
The Arabic tonal system is divided into 24 equal sections which form the basic Maqamat. Each Maqam is similar to a scale. It defines the range of tones and notes that will be used but the composer improvises around the range to create new sounds and varied interest in the piece. There are nine major Maqam families (or groupings) which are Ajam, Sikah, Bayati, Nahawand, Rast, Hijaz, Saba, Kurd, and Nawa Athar. These families are defined by their first lower Jins
Ajnas (اجناس) are the smaller building blocks of a Maqam. Each of these Jins (جنس) are a trichord (set of 3 notes), tetrachord (set of 4 notes), or a pentachord (set of 5 notes). Pentachords are sometimes refered to as 'aqd or 'uqud in addition to the term Jins or Ajnas. Each Maqam is made up of two main Ajnas, an upper and lower. The lower determines the Maqam family while the upper determines the dominant note. The Maqam also include secondary Ajnas which overlap the main ones and are exploited during modulation.
This is the same basic principle of the Persian Dastgāh (دستگاه) which is another modal system. The Arabic and Turkish Maqam systems were influenced by this system in the early period of the Sassanid empire. Although they are very similar slight differences do occur. For example the Persian Dastgāh has seven families: Se'gāh, Chahār'gāh, Rāst-Panj'gāh, Šur, Māhur, Homāyoun, and Navā. There are subcategories that some consider a Dastgāh on their own as well. Slight differences in the modulation techniques and pairings with rhythms more common to Persia/Iran also give Persian music it's own unique sound.
To learn more about the different Ajnas and Maqamat, visit the highly informative site Maqam.com