These are the open position Dominant 7th Chords. In music a Dominant 7th Chord is a chord that has a Root, a Major third, a Perfect fifth and a Minor seventh. It can be thought of as a major chord with the addition of a minor seventh. Dominant 7th chords tend to have a happy but bluesy sound. Below is a table of the of the chords above with notes that make them.
| Dominant Seventh Chord | Root | Major Third | Perfect Fifth | Minor Seventh |
|---|---|---|---|---|
| A7 | A | C♯ | E | G |
| B7 | B | D♯ | F♯ | A |
| C7 | C | E | G | B♭ |
| D7 | D | F♯ | A | C |
| E7 | E | G♯ | B | D |
| G7 | G | B | D | F |
