AKA: Db6, Db 6th, Db add6, DbM6, DbMaj6, Db Major sixth, Db major6, Db sixth
Major 6th chord
A major 6th chord is a four-note chord that contains the Root, the 3rd, the 5th, and the 6th of the major scale. In terms of intervals, a major sixth chord contains a major 3rd, perfect 5th, and major 6th. In other words, it’s a major triad with an added 6th.
The formula for major chords is R, 3°, 5°, 6°. For example, in C6 we have the notes C, E, G, A.
On a standard bass accordion, you can play major 6th chords by combining the Root with the minor chord of its 6th interval. For example, if C is the Root, adding an A minor you get a C6(5th omitted). You should add the major chord of the Root to get a full 6th chord but the 5th doesn’t add any tension so it can be omitted.
Major 6th chords are very common in pop, rock, and jazz music.
Db, F, Ab, Bb
R, 3°, 5°, 6°
Db + Bbm (C# + A#m)
4 + 2 or 5 + 2