Felix Mendelssohn - Wedding March - Boston Symphony Orchestra, Seiji Ozawa

Modern Arab. the theory recognizes the tetrachord as the basis for constructing a scale (4 sounds covering the range of a quart - pure, reduced or increased). Since in A. m. There is a special diatonic, the so-called "Neutral seconds" (they are located between large and small seconds and cover 3/4 tones according to the Arabic pitch designation system). For example, the “rast” tetrachordis common in A. m. Along with the whole tone includes two steps of 3/4 tones (s, d,e-quarter flat, f); in the bayati tetrachord these intervals are located differently (d, e-quarter flat, f, g). Expanded scale arises due to the coupling of tetrachords (the last sound of the first tetrachord is the first sound of the second), their combination (after an intermediate interval of a second) and crossing (in this case, tetrachords include two common tones). DOS Arab. scales (as well as their tetrachords) are named for them. and are built primarily from a certain tone (but can be built from other sounds). Tonality (high-altitude position) Arab. tetrachords and gammas associated with their structure.