Major seventh chord

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In music, a major seventh chord is a seventh chord in which the third is a major third above the root and the seventh is a major seventh above the root. The major seventh chord, sometimes also called a Delta chord, can be written as maj7, M7, Δ, ⑦, etc. The "7" does not have to be superscripted, but if it is, then any alterations, added tones, or omissions are usually also superscripted. For example, the major seventh chord built on C, commonly written as Cmaj7, has pitches C–E–G–B: It can be represented by the integer notation {0, 4, 7, 11}. According to Forte, the major seventh chord is exemplified by IV7, which originates melodically. The just major seventh chord is tuned in the ratios 8:10:12:15, as a just major chord is tuned 4:5:6 and a just major seventh is tuned 15:8. The minor flat sixth chord (minor triad with an added minor sixth) is an inversion of this chord.

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