Indulge not thyself in the passion of anger; it is whetting a sword to wound thine own breast, or murder thy friend.
A song must move the story ahead. A song must take the place of dialogue. If a song halts the show, pushes it back, stalls it, the audience won't buy it; they'll be unhappy.
And that will increasingly dawn on people. The demand for controlling the commanding heights will grow.

