A protest song is like a song that you sing to tell people about something that is not right or fair. It's like when you sing "no more homework" to your parents when you're upset about having too much homework.
Grown-ups also have things that they don't like, and they use protest songs to tell others about those things. For example, they may sing a song about how they dislike war or how they want everyone to have the same rights and be treated fairly.
These songs use words and music to help people feel the same way about an issue and join together to make a change that they believe in. It's like when you and your friends sing a song together to show how much you want something to change.
Protest songs have been around for a long time and have helped people make change happen in the world. They remind us that even just one voice can make a difference, especially when many people unite to fight for a common cause.