Imagine you're playing with a toy car on a big road that has lots of bumps and curves. If you imagine the toy car as a song, and the road as the melody, the way the car moves along the road is the melodic motion.
When we talk about melodic motion in music, we're describing how the notes in a melody move up and down in pitch. Just like the bumps and curves on a road, melodic motion can be smooth or bumpy. Sometimes the melody goes up quickly, then back down, like a roller coaster. Other times it moves slowly, gradually getting higher or lower.
There are also different types of melodic motion. A melody can move stepwise, which means it moves up or down by one note at a time. Or it can move in leaps, which means it jumps up or down by several notes at once.
Melodic motion is an important part of how we experience music. It can make a melody more exciting or calming, and can even help us remember a song more easily. So, just like you need to navigate bumps and curves on a road to get where you're going, a melody needs melodic motion to get us to the end of the song!