You will see a note appear on the staff. Play that note by touching the appropriate piano key. Since the keyboard is short you won't be required to play the correct octave. For example, if the note displayed is Ab you can play any Ab to answer.
You can choose which clef you want to learn - touch the clef choice button above the piano to change clefs. The "Change Difficulty" button at the top of the screen lets you choose from four levels of difficulty: you begin with only naturals written in the staff. Accidentals, ledger lines and key signatures are added as you progress.
A good companion for this and other Musica Touch™ exercises is our free multimedia textbook, Exploring Theory with Practica Musica (available for download at the iBooks store). You'll find a full explanation of how pitch notation works in Chapter 1.
Change keyboard options by touching the info button at the left of the piano, or by double-tapping the octave control at the top middle of the piano frame.
• You can use either the normal two-octave keyboard or the "fat keys" keyboard of one octave. As always, you can change the octave range of the keyboard by dragging the octave control left or right, but it will move automatically whenever the example note is out of range for the current setting. That allows you to see the correct key display if you touch the "show answer" button.
• If you're just starting out, you may want to use the labeled keyboard. Choose "show note names" in keyboard options.