DastgÃÂh (; , , ) is the standard musical system in Persian art music, standardised in the 19th century following the transition of Persian music from the Maqam modal system.
A consists of a collection of musical melodies, . In a song played in a given , a musician starts with an introductory , and then meanders through various different , evoking different moods. Many in a given are related to an equivalent musical mode in Western music.
For example, most in DastgÃÂh-e MÃÂhur correspond to the Ionian mode in the Major scale, whilst most in DastgÃÂh-e Shur correspond to the Phrygian mode.
In spite of 50 or more extant , 12 are most commonly played, with DastgÃÂh-e à  ur and DastgÃÂh-e MÃÂhur being referred to as the mothers of all .
Each consists of seven basic notes, plus several variable notes used for ornamentation and modulation. Each is a certain modal variety subject to a course of development () that is determined by the pre-established order of sequences, and revolves around 365 central core melodies known as s (each of these melodies being a ), which musicians come to know through experience and absorption. This process of centonization is personal, and it is a tradition of great subtlety and depth. The full collection of s in all s is referred to as the radif. During the meeting of The Inter-governmental Committee for the Safeguarding of the Intangible Heritage of the United Nations, held between 28 September – 2 October 2009 in Abu Dhabi, radifs were officially registered on the UNESCO List of the Intangible Cultural Heritage of Humanity.
The system of twelve s and s has remained nearly the same as it was codified by the music masters of the nineteenth century, in particular MîrzàAbdollÃÂh FarÃÂhÃÂni (1843âÂÂ1918). No new or large has been devised since that codification. When in the modern times an or a has been developed, it has almost always been through borrowings from the extant s and s, rather than through unqualified invention. From this remarkable stability one may infer that the system must have achieved "canonical" status in Iran.
The term has often been compared to the musical mode in Western musicology, but this is inaccurate. A is usually the name of the initial mode of a piece, which the music returns toâÂÂand moreover, a identifies a group of modes grouped according to tradition. In short, a is both the collective title of a grouping of modes and the initial mode of each group.
According to musicians themselves, the etymology of the term is associated with "the position () of the hand () [on the neck of the instrument]". The Persian term can be translated as "system", and is then "first and foremost a collection of discrete and heterogeneous elements organized into a hierarchy that is entirely coherent though nevertheless flexible."
In conventional classifications of Persian music, Abà « ÿAá¹ÂÃÂ, Dashti, AfshÃÂri, and BayÃÂt-e Tork are considered sub-classes of à  ur . Likewise, BayÃÂt-e EsfahÃÂn is a sub-class of HomÃÂyun, reducing the number of principal to a total of seven. A sub-class in the conventional system is referred to as .
A is more than a set of notes, and one component of the additional structure making up each is which pitches are singled out for various musical functions.
Examples include:
It's so named because it usually functions as the goal or destination tone that melodic cadences end on when they have a conclusory feel. This is also sometimes referred to as "tonic" but some authors avoid that usage because "tonic" is associated with Western tonality.
It's the pitch on which an improvisation in a usually begins. In some it is different from the finalis while in others it is the same pitch.
It's a pitch other than the finalis which often serves as the ending note for phrases other than final cadences
It's a particularly prominent pitch.
It's a variable note â one that consistently appears as two distinct pitches, which can be used alternately in different contexts or at the performer's discretion.
Most scholars divide the traditional Persian art music to seven s. Others divide them into 12 s by counting Abu Ata, Dashti, Afshari, Bayat-e Kord and Bayat-e Esfahan as separate s rather than subcategories of other s.
Those who categorize the traditional Persian art music into seven often also list seven (, which means songs) in conjunction with these s.
The following is a list of the seven s and seven es:
There are listed in order as per the radif (music) of Mirza Abdollah.
Flats are shown with a óâÂÂó. Koron (half flats) are shown with a ópó.
Less common are:
Note that in some cases the sub-classes (s) are counted as individual s, yet this contradicts technicalities in Iranian music.