Watch the Mixolydian online guitar lesson by Robbie Calvo from Modal Expose
The A major scale from E to E
E F# G# A B C# D E. The bold letters are the chord tones of an E major triad and an E7 chord with the fourth note added. These notes also constitute the chord arpeggio and are your strong resolution points over those chords.
Let's locate and play an E7 arpeggio in position from our A major scale shape. Sounds very strong and resolute.
Play the A major scale now from E to E over the E7 backing track and you will hear that the tonal center of the chord, arpeggio and scale are that of the E7 tones. This is the E mixolydian mode.