Some of you might recall that on the DSi and 3DS eShop, there was an Animal Crossing Clock that cost $1.99. I happened to buy it because the 3DS didn't have a built-in alarm clock, and I used that alarm clock to wake up early every morning for band/school for about five years straight.
Every.
Day.

The alarm clock used tunes from City Folk, including an hourly theme (I forget which), the Resetti theme and the "bug caught" theme. They're very recognizable, and many of them start out with a whistle or short melody.

As it turns out, several years later (coming on a decade, I reckon) I still get woken up by these songs when I hear them even though I don't use that as my alarm anymore. If I'm watching a City Folk video and someone catches a bug, that whistle makes me snap to alertness, because it's time to get up!