Group piano is when a bunch of kids sit around a big piano together and learn how to play music.
Imagine you and your friends sitting at a big table, but instead of pencils and paper, you have a full sized piano and a teacher to guide you.
Everyone gets their own small section of the piano, and the teacher shows you how to put your fingers in the right place to make the different notes.
You can all play together or take turns practicing on your own section. As you get better, you can play more complex songs with your friends.
It's like having a mini band and learning how to make beautiful music together!