As a triad is referred to in the music a three-part chord, which consists of stacked one-third octave intervals. A triad consists of root, Terzton and Quintton.
Since one "large" and " small " Third differs, there are four possibilities, two thirds aufeinanderzuschichten. The resulting triad types are named after their scale type or according to the size of their frame interval:
Due to the frequency ratios of 5:6 for the minor third, 4:5 for the major third, and 3:2 for the fifth in a natural atmosphere, many overtones coincide in the spectrum of major and minor triad. The spectrum of these two triads is therefore relatively simple and they are perceived as harmonious and pleasant.
If another Dreiklangston heard as the keynote in the bass, one speaks of a reversal. At the first reversal, called Terzsextakkord which Terzton is in the bass, the second reversal, called six-four chord, which lies in the bass Quintton.
Triads on scales
About every note of a scale can be (so-called diatonic tones ) form triads by Terzschichtung of tones of this scale. The stage theory and function theory thus focuses in detail.