Build a Retro Musical Toy — Kids Toys | Make:

Perhaps the most iconic 80’s music toy was the Magical Musical Thing from Mattel. The TV commercial featured a kid playing melodies with one finger on the toy’s keypad strip — and finishing by playing it with his head! It featured a sound circuit that was designed around the cheapest and most basic building block of digital electronics: the 4049 CMOS hex inverter chip.