Build a keyboard, a voice changer, oscillator, alarms, and even play music while studying sound, pitch, air pressure, capacitance, and resistance. Learning about electricity is fun with easy-to-understand Snap Circuits. Students build circuits by snapping together pieces on a special grid. A detailed instruction manual is included with directions for 188 projects, full-color diagrams, science learning tips, and a seven-page background section about understanding electricity and sound in the world around us. Four AA batteries are required and available separately.