I have always been fascinated by the power of repetition. You can alternate playing a C & an F chord & repeat it over & over for ten minutes & it just starts to sound better & better. Or listen to Ring the Bell, the six minute, two-chord Songs: Ohia song. It builds & builds & its force is never diminished, it only grows.
Elizabeth Hellmuth Margulis wrote an illuminating piece about this power, read it here.
Ring the Bell: