1. I–V–vi–IV (C G Am F): hopeful, anthem-like — countless pop songs.
  2. vi–IV–I–V (Am F C G): emotional, the same chords starting somewhere sadder.
  3. I–vi–IV–V (C Am F G): nostalgic, '50s and '60s.
  4. ii–V–I (Dm G C): smooth and jazzy — try it with seventh chords.
  5. i–VI–III–VII (Am F C G in a minor key): dark and driving.