The app keeps marking random notes wrong (red) in each lesson even though I don't play anything. How do I fix this?

Please reconfigure your keyboard to the Playground Sessions app if you are seeing one or more red notes at the start of each lesson.

Windows and Mac Computers:

1. Quit the app.
2. Unplug your keyboard from your computer and shut it off.
3. Turn the keyboard on and plug it in.
4. Open the Playground app.
5. Go to Edit - Configure MIDI Keyboard. 

If the issue persists, please read this article.

iPad:

1. Quit the app.
2. Unplug your keyboard from your computer and shut it off.
3. Turn the keyboard on and plug it in.
4. Open the Playground app.
5. Go to Settings - Piano and select your keyboard.

If the issue persists, please read this article.