When fans heard that “Once Upon a Time” Season 6 would feature a musical episode, they were shocked and unsure. Could the cast sing? Would this be some cheesy attempt at boosting the ratings for a sinking show? However, once they found out that “Once Upon a Musical” would feature the wedding of Emma and Hook, fans were excited.

That event is now coming to screens. This coming Sunday will see the two finally tie the knot in singing style. Just how does the musical start happening? The promo explains all.

When you wish upon a star…

The “Once Upon a Time” promo makes it clear that Snow will wish upon a star.

It’s the time that the first curse is about to take place, and Snow needs help to make sure her daughter is ready to be the savior. That wish turns the whole of the Enchanted Forest into a magical adventure.Considering the fact that the show is based on fairytales, a musical episode shouldn’t be that surprising. Thankfully, it looks like the music is mostly sticking with the Enchanted Forest, where musical numbers will make sense. This is a land of magic, wishes, and dreams. There will be some musical elements within Storybrooke as well, as a featurette from the episode shows that Jennifer Morrison will sing at least one song.

Songs from all the main cast of ‘Once Upon a Time’

It turns out that the majority of the cast can sing.

At least, the trailer makes that look likely. There are moments of Snow, Charming, The Evil Queen, and Zelena singing songs. Even Hook has a musical moment on what looks like his own ship—suggesting that this will take some time in a memory of the Enchanted Forest.

The only main cast members who aren’t seen singing are Rumple and Belle.

It is possible that they have a few numbers, but the main focus is on the Charmings right now. This is meant to be the wedding of Emma and Hook, after all. The Black Fairy is spotted in the featurette, but she may not have a big role in the episode.

It’s time for a wedding

Of course, the biggest part of the episode is Hook and Emma’s wedding.

This is something “Once Upon a Time” fans have been waiting years to see. While there are some who would have liked for the wedding to take place at the end—after the defeat of The Black Fairy—this timeline does work. There is no guarantee that Emma will get out of this battle alive.

This season has constantly made it clear that the savior’s fate is to die. That means Emma is likely to die at the end of the show, possibly through a sacrifice to get rid of the biggest evil Storybrooke (and the Enchanted Forest) has ever seen. Tune in on Sunday at 8 p.m. on ABC for “Once Upon a Time” season 6.