Mixolydian
Mixolydian is a major mode with a b7 instead of a natural 7, one shade darker than Ionian. That flattened 7th is the sound of the dominant chord and of countless blues and rock melodies.
5th mode of the Major scale
Major
Intervals
1 2 3 4 5 6 b7
Chords
Triads
7th Chords