The raw analog waveforms of a vintage Magical Musical Thing children’s synthesizer.
The Magical Musical Thing was produced by Mattel, and invented by Franklin Eventoff, inventor of the Force-Sensing Resistor. Franklin now runs a company called Sensitronics that produces sensors. The oscillator contained within the MMT is based on a 4049 CMOS hex inverter chip.
This library works with the free Decent Sampler player plugin.
https://www.decentsamples.com/product/magical-musical-thing-sample-library-free/