Computer Audio Spectrum Analyzer in 1981?

Radio Shack Cat. No. 26-3156 Audio Spectrum Analyzer for the TRS-80 Color Computer Released in 1981

A friend gave me this cartridge and I was honestly impressed with what it could do. An actual spectrum analyzer on a computer released in 1980? (The Color Computer 2 was released in 1983 but it is identical in function to the original but is just cost reduced.)

You can see this catridge in action in the movie Revenge of the Nerds when the guys play the finale song for the entire school. (They also show a Coco 2)

Update: Reddit user CheapScotch confirmed that this is 100% software based. People had produced both a tape and disk version of this software which you can find online. He tried one of these on his Coco 2 and it worked perfectly. (It is just a 4K ROM.) This shows that there is absolutely nothing in the cartridge other than a ROM and the Coco is able to do all of this using built in 1980 technology.

I was using an Apple II+ back in the early 80s and I never saw anything close to a real spectrum analyzer for that system, so I'm delighted a 1980 Coco could do it.

This cartridge works surprisingly well, especially for a machine that is that old. ... https://www.youtube.com/watch?v=kQcClC1KP-o