answer
Totaka's song is a short melody that Kazumi Totaka, a sound designer at Nintendo, sneaks into every game he works on. It's usually played when you sit around on one particular screen for a long time, for example Richard's Villa in Link's Awakening, or the post-credits "the end" screen in at least one game (can't think of any examples but i know it exists)
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re: other examples re: answer
@The1AndMany I definitely didn't know the smash one! That one's neat.
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