Ticket 60: The Seven Drop

Start on the root chord but immediately drop down a semitone to the 7th chord in the scale. This will produce a disconcerting "where are we?" effect. For slightly different flavours try the VII7, vii or vii7, or even the dim7 or half dim7. This songwriting trick is covered in much more detail here.

I'm So Tired - VII
Martha My Dear - VII
Sexy Sadie - VII7
Yesterday – vii (or VIIsus4?)

also

Karma Police – VII (Radiohead)

See also

Golden Ticket: The Seven Drop
Ticket 1: Use The Flat 6 (bVI) Chord
Ticket 7: Avoid Using All Three Major Chords Early In The Song
Ticket 8: Use The Minor 4 (iv) Chord
Ticket 28: Use At Least One Out Of Key Chord
Ticket 43: Use The Fourths Luke!
Ticket 44: Use the Minor 5 (v) Chord

See the full list of songwriting tips here - Tickets To Write