Another chord type you will need to know is the minor seventh. The minor seventh chord symbol is m7. Here are the most common open chord shapes for m7 chords.
Dm7
To play the Dm7 chord, use all four fingers of your left hand as shown in the diagram. Strum all four strings.
Rhythm Pattern
Am7
To play the Am7 chord, strum all four open strings. No fingers are required for this chord.
Rhythm Pattern
Em7
To play the Em7 chord, use the second and third fingers of your left hand as shown in the diagram. Strum all four strings.
An Em7 chord is used in this exercise.
Rhythm Pattern
Here is a Blues progression using minor 7th chords. Notice also the use of Fmaj7 and E7. In many Blues and Jazz songs, most of the chords are sevenths.
Rhythm Pattern