Major chords consist of 1, 3 and 5 sounds of the major scale
Minor chords are composed of the 1st, ♭3rd and 5th sounds of the Major sequence. ♭3; the third voice of the scale consists of half-voice giving up (flat).
Diminished chords consist of, 1st, ♭3rd and ♭5th sounds of the major scale. ♭3 and ♭5t the third and fifth tones of the scale are played by half the voice giving up (flat).
Augmented chords consist of 1st, 3rd and #5th sounds of the major scale. The fifth voice of the scale is composed by playing a half-voice treble.
Examples for Notes
C - E - G consists of notes.
C - Eb - G consists of notes.
C - Eb - Gb consists of notes.
C - E - G# consists of notes.