Persian Modes: Reading Between the Lines of Western
|Western interval (Abr.)||Persian interval (translated)|
|1/4 tone||half aug 1st|
|øM2 = 3/4 tone||half Major 2nd|
|5/4 tone||over Major 2nd|
|øM3 = 7/4 tone||half minor 3rd|
|9/4 tone||over Major 3rd|
|11/4 tone||half aug 4th or over dim 5th|
|4+ or 5-||aug 4th or dim 5th|
|13/4 tone||over aug 4th or half dim 5th|
|15/4 tone||half aug 5th|
|øM6 = 17/4 tone||half Major 6th|
|19/4 tone||over Major 6th|
|øM7 = 21/4 tone||half Major 7th|
|23/4 tone||half dim octave|
Table 1: Persian intervals vs. western intervals
Like western music, the modal system in Persian music is also built upon tetrachords (Dāng). But there is an important difference. In order to build up scales in western music, tetrachords juxtapose by having one whole tone interval in between. In Persian music scales, tetrachords juxtapose immediately beside each other. for example:
in western music, two Dorian tetrachords (tone-halftone-tone) build up this scale having C as the key: C-D-Eb-F-G-A-Bb-C
in Persian music, two tanini-baghiye-tanini tetrachords (which is similar to western Dorian tetrachord) build up this scale with having C as the key: C-D-Eb-F-G-Ab-Bb-C (Octave C does not belong to none of tetrachords. It is added for sake of tonic note).
So in Persian music two tetrachords do not automatically repeat the tonic note (in 1st degree) in 8th degree.
At the following the intervals for all Persian modes are provided. As you see in diagrams, in each Persian mode by moving one quarter tone high or low for certain degrees we arrive at western modes.
It should be noted that the presence of quarter tones in Persian modal system is only in form of 3/4 tone intervals. A single 1/4 (actual quarter tone) is used nowhere within one mode.
At the following charts, solid lines denote western tempered intervals and dashed lines denote Persian intervals. The ø symbol represents the term "half" mentioned above. e.g. øM2 = 3/4 tone interval = one quarter tone lower than Major 2nd interval or 4ø+ = 11/4 tone interval = one quarter tone lower that 4+
I think the importance of these diagrams is if you are familiar with western modal systems and are skillful in performing them on the instrument, you can easily modulate to a neighbor Persian mode. And more excitingly you can even re-modulate to another related western mode from there. As an example consider you are playing E Phrygian. Now you can modulate to E Nava by making II degree one quarter tone higher. From there you can re-modulate to E Natural Minor by making II degree in quarter tone higher.
Also notice that by changing the tonic degree, you can find numerous other Persian modes that however that have no associated name in Persian modal system, but they relate to other Western modes. e.g. while you don't see Dorian in the following charts related to any Persian modes, you can use the chart for Abu-Ata if you associate the tonic to degree VII . So you can use G Abu-Ata with its tonic on A (Shāhed on A) as a mode closely related to A Dorian - with only quarter note difference in A Dorian's third degree.
It should be noted that using non-equal temperament systems are also prevalent in Persian music that is not subject of this article.
Shur (Shūr) comes between Phrygian b5 & Natural Minor
Abu-Ata (Abu-Atā) comes between Phrygian & Natural Minor
Bayat-e-Turk (Bayāt-e-Turk) comes between Natural Minor & Mixolydian
Dashti-variation#1‡ comes between Phrygian & Natural Minor
Dashti-variation#2‡ comes between Phrygian b5 & Natural Minor
Nava (Navā) comes between Phrygian & Natural Minor
Segah (Segāh) comes between Phrygian b5 & Mixolydian
Chahargah (Chahārgāh) comes between Mixolydian b2 b9 & Mixolydian
Homayun (Homāyun) comes between Dorian b2 b5 & Dorian
Bayat-e-Esfahan (Bayāt-e-Esfahān) comes between Phrygian Major & Mixolydian b6
Mahur (Mahūr) and Mixolydian are the same†
The following two modes span above one octave. They contain 3 tetrachordes.
Rast Panjgah (Rāst Panjgāh) and Mixolydian b6b9 are the same†
Afshari (Afshāri) comes between Natural Minor b5 b9 & Mixolydian b9
(C) Jun 2011, Salim Ghazi Saeedi