procedural generation – How to produce songs with chicken sounds?

I work in a game with chickens and I would like Chicken to sing songs, quite similar to those of Gonzo Chickens of "Muppets show". But I have a hard time finding a way to do it.

I've found this cat keyboard that does something similar to what I want, but it produces meow cat sounds.

Any advice on this? If there is no instrument, a way to do it by software? maybe with a MIDI keyboard?