Chord Construction

Let's take a look at the chord tones of some G extended chord shapes.  All these chords will have the same root of G, for comparison purposes.

Gmaj7

Gmaj7 is built with G B D F#, the 1st, 3rd, 5th, and 7th notes of the G major scale.

G7 is built with G B D F, the 1st, 3rd, 5th, and b7th notes of the G major scale.

Gmin7 is built with G Bb D F, the 1st, b3rd, 5th, and b7th notes of the G major scale.

Gmin7b5 (G half-diminished 7th) is built with G Bb Db F, the 1st, b3rd, b5th, and b7th notes of the G major scale.

G7sus is built with G C D F, the 1st, 4th, 5th, and b7th notes of the G major scale.

Gdim7 is built with G Bb Db E, the 1st, b3rd, b5th, and bb7th notes of the G major scale.