It's one of the most famous musical passages ever written. Ludwig van Beethoven starts his Fifth Symphony with four percussive notes, then spends the next four movements inventing new ways to make them sing.
Using four notes as the undercarriage of an entire symphony was a revolutionary idea when the piece premiered in 1808. So was the introspective writing that makes the music so indelible.
Watch a performance
Watch Daniel Barenboim conduct Beethoven's Fifth Symphony in 2012 at the BBC Proms: