In music theory, a major chord is a chord having a root, a major third, and a perfect fifth. When a chord has these three notes alone, it is called a major triad. Some major triads with additional notes, such as the major seventh chord, may also be called major chords.
A major triad can also be described as a major third interval with a minor third interval on top or as a root note, a note 4 semitones higher than the root, and a note 7 semitones higher than the root.
A major chord in just intonation is tuned to the frequency ratio 4:5:6, while in equal temperament it has 4 semitones between the root and third, 3 between the third and fifth, and 7 between the root and fifth. It is represented by the integer notation 0,4,7. In equal temperament, the fifth is only two cents narrower than the just perfect fifth, but the major third is noticeably different at about 14 cents wider.
The major chord, along with the minor chord, is one of the basic building blocks of tonal music and the common practice period. It is considered consonant, stable, or not requiring resolution. In Western music, a minor chord, in comparison, "sounds darker than a major chord".