Adding major sevenths to chords can be the equivalent of letting in more colour and sunlight. Basic chordal character and ...

Try to play this interval on a keyboard or piano. A chord is a group ... In this example you will hear both chord I of C Major, and the dominant 7th chord. You can follow along with the notation ...

Where the major seventh differs, is that it is only one semitone below the keynote, so in a chord of C major 7, the ‘major’ refers to the actual note and not the major/minor tonality of the chord.