Major seventh chord
A major seventh chord is a tetrad comprising a root, major third, perfect fifth, and major seventh.
In just intonation
In the 5-limit:
- 8:10:12:15 is found on on the I (1⁄1) and IV (4⁄3) of Ptolemy's intense diatonic scale (Zarlino), perhaps the most common 5-limit diatonic.
In the 3-limit:
- 128:162:192:243 spans five octave-reduced fifths, and may be considered a 3-limit approximation of 8:10:12:15.