Mixolydian
A major mode with a flat 7th — bluesy and laid-back
Mixolydian is a major major mode with a flat 7th — bright like major but with a bluesy, laid-back edge. The ♭7 adds a raw, earthy quality, and makes it the natural home of the dominant 7th chord.
Built on the 5th degree of the major scale. Its major pentatonic subset is shared with ionian and lydian; the 4th and ♭7 define Mixolydian's character, the ♭7 being the signature note.
Common in blues, rock, folk, Celtic, country, funk, and jam bands — the natural habitat of the dominant V chord.