Popular Photos. Pocket Piano | Critter & Guitari. The Pocket Piano is a mini electronic synthesizer with a big sound! The synthesizer features six unique modes: • Vibrato Synth • Harmonic Sweeper • Two-Octave Arpeggiator • Octave Cascade • Mono FM Synth • FM Arpeggiator The Pocket Piano is housed in a sturdy aluminum and hardwood case and also includes a built-in speaker, a 1/4" output jack, and wooden keys made for a refined touch. It can be powered both by a 9V battery or a 9VDC Power Supply (not included). When you change modes with the right-most wooden button, a color LED above that button indicates what mode is selected with a different color for each mode. Chords for Pocket Piano! Example Sounds. FoldingStory | The Group Storytelling Game. My Modern Metropolis.