Have you ever heard a song and thought to yourself: "I've heard this before somewhere, I could have sworn it." But just can't remember where from? While the music world is incredibly creative and varied, some melodies seem to reoccur and reused throughout the decades and centuries. This list of 24 songs is divided into 2. 12 songs with the original melody, and 12 more modern songs that have used it to create new music. Enjoy!