Ok kiddo, so a long long time ago, people didn't have things like MP3 players or radios to listen to music. Instead, they would make their own music by playing instruments like flutes and drums.
In some places, like in the military, they would have a group of people that played these instruments together, called a "corps." The corps would march and play music during parades or when they were going to battle.
These types of corps were especially popular in Europe hundreds of years ago. They would use special types of flutes called "fifes" and drums that were sometimes made out of animal skin.
The people who played in these corps would learn special songs and routines so they could all march and play together. It was really important that they all played together because it sounded much better and made them look really impressive.
Even though we have different types of music and instruments now, some people still like to play in ancient-style fife and drum corps. It's a really cool way to keep history alive and share some really cool music with others.