Glad you asked. So, the sung parts would be when Green encounters the animals, zombies, villagers and wandering trader.
What would be spoken would be Green trying to talk to Purple, the latter bringing up his backstory with Flashback dialogue from younger him and his parents, and the where Green comforts Purple.
I am debating whether Purple's journey would be sung if the characters could speak/sing. In other words, think of the episode like a Broadway musical where some parts are sung and some are not.
