My Facebook profile said: "Jenifer Toksvig has written that song. Done. Finished. (For now. Draft one. But, you know... done.)"
James Marler replied: "When is a song ever done? (and this is a serious question for Toksvig the kick-ass musical theatre professor type)"
The Law of Conservation of Matter also applies to stories, so:
- just as matter cannot be created or destroyed, but is simply rearranged and redistributed...
- so stories and songs are made through rearrangement and then they are redistributed to audiences...
- and the audiences are made up of people who have the potential to be emotionally rearranged by the stories and songs, which they might then redistribute in some way to others...
So in answer to your question, James:
A song is done when it has mattered.