User blog comment:ArtDraw12/TD Theories: What if "if you don't sing, you're out" rule was taken seriously?/@comment-22535514-20161031194753/@comment-11883116-20161031195800

That'd be 21 episodes max and nine episodes minimum, actually. Depending on the version and which characters were eliminated and when, the plot could've been changed drastically at some points. In fact, there's a chance regular eliminations would've been different.