In styles other than Blues and Jazz, Dominant 7ths are most commonly built on the 5th degree of both major and minor scales. In this situation the chord is described as . The following example demonstrates an E7 chord (notes E, G#, B and D) as chord
in the key of A minor. All of the notes of the chord are contained in the A harmonic minor scale. It is simply an E major triad with a D note added a minor 3rd above the B. The chords used here are the three primary chords in the key of A minor.
To familiarize yourself with 7th chords in all keys, play all four inversions around the key cycle until you are comfortable with them. The following example uses inversions which are close together on the keyboard. This produces the smoothest sound and is also more practical than jumping around for the sake of keeping the same inversion for each chord.