Lot666 said: "How does this work, i.e., how does the union determine a required minimum number of musicians for a given show?"
This goes back to the Broadway strike in ‘03.
https://www.playbill.com/article/broadway-musicals-and-the-strike-your-questions-answered-com-111973
“What do the musicians want?
They want producers to continue guaranteeing that a minimum number of musicians will be employed in each musical based on the size of the theatre. Doing away with these minimums, they say, will mean producers can shrink orchestra sizes and/or use synthesized music to make up for it. There are other contract issues, but this is the major sticking point.
What do the producers want?
Producers say the union should not be dictating the artistic needs of a musical, and that minimums create the possibility that musicians who are not needed or used will be paid, which inflates the running costs of the show. The producers first wanted minimums eliminated, then offered to agree to a minimum orchestra of 15 for Broadway's biggest houses. The current minimum at major houses is 24.“
The result came to a reduction of minimum number of musicians from 24-26 to 18-19, from what I understand.
I am big. It’s the REVIVALS that got small.