Paul McCartney opened up about how he wrote a lesser-known Beatles track with what he called 'naughty' chords.

Guitar skills: 'Add’ chords come in the form of either ‘add9’ or ‘add11’. The name tells you to add either a 9th or 11th interval to a basic major or minor chord. So, Cadd9 is a C chord ...

All the chords built on other notes in the scale of C are minor, except chord VII - the notes B – D – F, which is diminished. When a seventh is added to a chord this is known as a seventh chord.