Iranian dastgah music developed mostly during the Qajar era. Similar to modal music traditions, Iranian music consists of several makams (modes), called gooshes. Gooshes combine according to their modal characteristics into modes, called dastgah and avaz. Some gooshes may introduce a modulation into the dastgah, while others are simply recognized rhythmic or melodic patterns within same modal structure as the parent dastgah. Different dastgahs call for particular tunings and intervals, and so the characteristic instruments tar and santoor both have adjustable intonation.