"Major 6thはどのような性格タイプですか？ Major 6thは、ISFJ in MBTI、6w5 - - in Enneagram、RCUAN in Big 5、 in socionics のパーソナリティタイプです。"
A major sixth chord is a major chord with an added major 6th above the root. It has a quite nostalgic sound.
