When you’re using this app you can say that you know to play piano. As the same says it is a magic piano which will allow you to play the music. You just have to select a song and tap the screen to play the music.
Search for Magic Piano from App store to download this app for free.
Here are some of the screenshot’s of this app, where it says – tap the screen to play the music. So when you select a song and just tap the screen you can see the magic this app does.
Also it allows you to select a variety of songs, some of them are free and some are paid.