1. Launch the app and select "Play" to start a new game.

2. Choose a song to play from the list of available songs. There are many different songs to choose from, including classical music and popular songs.

3. Once you have selected a song, the game will display a piano keyboard and notes that you need to play.

4. Use your fingers to tap the correct keys on the piano keyboard to play the notes.

5. The game will rate your performance based on accuracy and timing, and give you a score at the end of the song.

6. The game can have multiple levels, and as you progress, the songs will become more challenging with more complex notes and faster tempos.

7. You can also use the "Free Play" mode to practice playing the piano without any specific song.