Imagine a young Alexandre Guilmant arriving at his composition lesson having written the following piece ...
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His composition teacher (Jacques-Nicolas Lemmens, if we can trust Wikipedia), thoughtfully scratches his beard and says, "Well, young Alexandre, this theme is rather nice but it lacks a certain Je-ne-sais-quoi "
He pulls out his pen and, with great flourish, adds a few notes to spice things up a bit...
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"Oui, oui!" shouts Alexandre. Now I see! This piece has interesting notes in it. I shall become a famous composer!"
Soooo, when you play this piece (or any piece), be sure to aim at those cool notes.