Mugam is a tonal system, the twelve tone system of Azeri folk-improvisational music for voice and stringed instruments, and can be traced back to the 13th--14th centuries.
It is considered to be the most perfect of the styles in the music of the Eastern Renaissance for its melodious development.
There are now only sevel classical mugams left out of twelve.
The mugam is an inseparable part of the spiritual and civil music of Islam (mournful psalms, ritual, and prayer music).
The scale of the mugam Bayati--Shiraz (which means The Song of Shiraz) coincides with the European harmonic minor, and there is a remarkable similarity with the theme of Bach's famous Toccata in D Minor for organ.