Grease Live was the musical you should have watched on Sunday night, with some knockout performances and slick production values. But what does it take to pull off such a complicated broadcast? Well, this video from the show's associate director Carrie Havel shows you a small slice of the action, with Havel coordinating the live footage — singing along to "Great Lightning," but with all the lyrics replaced with camera numbers:

A lot of people have asked what it means to be the Associate Director on a show like Grease Live. Here's a peek behind the curtain. Every shot in the show was designed and scripted by our director Alex Rudzinski. My job was to execute that plan. You hear me calling shot numbers and camera moves carefully coordinated with the music. My head stays in the script and Alex, to my right, keeps an eye on cameras to adjust framing and pacing. #GreaseLive Posted by Carrie Havel on Monday, 1 February 2016

And here's Havel's description of what's happening:

"A lot of people have asked what it means to be the Associate Director on a show like Grease Live. Here's a peek behind the curtain. Every shot in the show was designed and scripted by our director Alex Rudzinski. My job was to execute that plan. You hear me calling shot numbers and camera moves carefully coordinated with the music. My head stays in the script and Alex, to my right, keeps an eye on cameras to adjust framing and pacing."

As The Verge's Christopher Plante and Jamieson Cox noted in their review, live broadcasts of this type are pretty uncommon and take a hell of a lot of skill. Havel's role is obviously impressive, but just think: coordinating the cameras is only one part of the performance, which included big dance numbers, lightning fast costume changes, and a shooting location so large that golf carts were needed to transport actors between scenes. It just goes to show that when it comes to live performances, the choreography behind the scenes is usually as impressive as what's on stage.