Once Upon a Time: Go behind the scenes of the musical episode

The Once Upon a Time musical episode is upon us!

During Sunday’s episode, the residents of Storybrooke and the Enchanted Forest alike will be singing. See, prior to Emma’s (Jennifer Morrison) birth, Snow White (Ginnifer Goodwin) made a wish upon a star to protect their daughter, resulting in their entire kingdom bursting into song, which infuriates the Evil Queen (Lana Parrilla) to no end. In Storybrooke, meanwhile, the Black Fairy (Jamie Murray) aims to unleash another curse on the town as Emma and Hook (Colin O’Donoghue) prepare for their wedding.

Get a behind-the-scenes look at how the musical came to life — including a sneak peek of Morrison’s solo, “Emma’s Theme” — in the featurette below:

Once Upon a Time‘s musical episode airs Sunday at 8 p.m. ET on ABC. In the meantime, here’s everything you need to know about the hour, which will feature Emma and Hook’s wedding. Plus: Check out the full track list, photos from the hour and a sneak peek at Hook’s number, “Revenge Is Gonna Be Mine.”