What kind of stage directions should go into a libretto? I've always tended toward a "less-is-more" approach, leaving wide latitude for directors and performers. Still, you have to give them something to hang their hats on, as it were, while still letting them make the work their own.
There's also a question of intention. If I as the writer do not specify my intention, then I am leaving it open to interpretation. Part of my job is, in a sense, to prioritize. The more important, crucial, non-negotiable elements certainly go into the libretto. Explicitly spelled out for all to see. A warning to interpreters: "ignore at your own risk."
The key elements that I have, over time, come to include as a matter of course include:
- The physical setting of the action, or the performance environment if working in a non-traditional manner
- Some hint as to character backgrounds beyond the words and actions we see—hidden or unconscious motivations make for powerful drama
- Key pieces of action and movement, the sine qua non elements, because they reinforce what's in the text with action which can help consistency and believability or crucial actions that are not reflected in the text but necessary to convey a desired meaning or motivation
Since opera is a generally collaborative endeavor and a librettist usually collaborates with a composer, here are some other thoughts on stage directions:
- Stage directions often have musical implications: how the music interacts with the action and how the timing works out
- The flow of time in opera varies between real and un-real; how will that affect the actions and motions of the character?