Music Note's and Key's Flashcard. Clef's / Key's: Treble, Bass, C-Alto With 15 Key's Each. Range: Low E to High F Meter: 1 to 300 bpm Toggle Note or Key Name Display. Help in Device Menu. USE: Use Default or Select Clef, Key, bpm - Then Step or Run. Defaults: Treble Clef, Key C, 1 bpm.