About 20 years ago, it was the Furby a huge hype, but in hindsight were the furry critters rather annoying than smart. Unless, of course, re-scheduling and there is a musical instrument with builds.
That last one is recently done by Sam Battle, a musician, programmer and hacker. He collected 44 Furbies, and there built an organ. A 45th instance acts as a conductor. his YouTube channel Look Mum No Computer Battle to see the result and hear.
In the first instance, it seems like a creepy adaptation of an old fad, but the work of Battle is to be a genius to put away when simple tinkering. Are Furby-organ is actually able to use music to bring forth and that has a lot of (programming)work. Each Furby has its own pitch and key, there must be a lot of time and effort in posting it. The result is pretty genius.