The main difference, generally speaking, is that a musical tells a story with song and dance, while a play typically sticks to spoken dialogue. This is a broad generalization; some plays feature musical content, and some musicals feature heavy amounts of spoken dialogue.
Answer:
One benefit of using halogen light bulbs in lighting fixtures for filming is that they have an even color temperature. Which means the light looks even and consistent on film. Halogen bulbs also live longer than incandescent bulbs. Which means you can use them longer and possibly save money.
