This is very, very silly - but great fun to play with ;-)
https://artsandculture.google.com/experiment/blob-opera/AAHWrq360NcGbw?cp=e30.
After you've started getting the bass blob to sing, the tenor one will soon drop into place. A bit more playing finds the mezzo soprano joining in, followed by the soprano.
With a bit of practice it's possible to get them all singing in harmony, and counter-harmony too, and actually remarkably sounding like a real opera.
Go on, give it a go ;-)