How Latin was Replaced by Italian

Check out this fascinating reply to the question "When did Italian become the language of Italy?"

“...so, it can be said that the evolution of Italian did not take place directly from Latin, but rather it arose from the need for a new “common language” understandable by all the inhabitants of the Italian peninsula, that replaced the disappearing Latin over a background of thousands of different languages and dialects that were the evolution of the vulgar versions of Latin spoken since Roman times. And it can be said that literature and poetry were the greatest drivers behind the making of Italian language, which probably is part of the reason for its musicality.”