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

This funky F chord features in 1999 and is a variation ... in the ‘Hendrix’ shape, the Sexy MF guitar part occasionally hits ...

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.