User blog comment:Bowser & Jr./If Phineas and Ferb Went Outside the Ordinary.../@comment-5137023-20100925213756/@comment-844113-20100925213959

I think it's implied as an actual musical, like AVPM or something.

Imagine that. AVPM, as A Very Phineas Musical. *begins writing scripts and plans to get the whole wiki together IRL to perform it*