Gold Label Maestro Mouse with Baby Grand Piano Gold Label Maestro Mouse with Baby Grand Piano. Using the newest Radio Frequency Identification technology, Maestro Mouse can play 24 favorite Christmas tunes on his baby piano. As he plays the keys move. Place one sheet of the holiday music sheets on his piano to have him talk and play your selected song. Presence-activated. Approximately 9 1/4-inches wide. Battery operated. Individually gift-boxed--making it the perfect gift!