The best ad lib moments are fully scripted.
With the bombardment of messages humans face every day, you have to ensure your messages are framed powerfully and delivered flawlessly. No one has the time or budget to simply "hope" they all got through.
When you need to focus all attention on a series of large messages, you are building a show for an audience. Being able to intentionally and authentically focus that attention has been the craftwork of musical concerts, theater performances, even full length movies for decades. Enter stage right: the event.
Today's experiential design (XD) necessitates a strong background in show development: scripting, plot lines, character development, audience engagement, stage blocking, emotional crescendos. If it is pure spectacle you are looking for, or simply powerful messaging, you need a team who understands "the show."