ET on ABC, is titled “The Song in Your Heart.”
Here’s what else you better know:
ENTERTAINMENT WEEKLY: Why is everyone breaking into song?
The singing and the musical is tied directly to Emma.

Credit: Jack Rowand/ABC
Why did you decide to do a musical for Emma’s wedding?
When we started talking about the musical, we wanted it to be a special episode.
We thought Emma’s wedding felt like the natural milestone for us.
HOROWITZ:It felt like the right place.
We’re trying to move toward something.
It builds to that wedding, whichlike everything in the episodewe hope is filled with a few other surprises.
What can you tease for some of the songs we’ll be hearing?
KITSIS:The songs are all original.
They’re specific to each character.
The composers did an incredible job.
So we’re really excited about it.
KITSIS:And they’re catchy.
Are the characters aware that it’s odd that they’re singing?
Do you go meta in that sense?
KITSIS:I would say yes.
HOROWITZ:Yup, it’s not just like singing and nobody acknowledges that songs are happening.
When it came to singing and dancing, was there anyone in the cast who surprised you?
KITSIS:Yes, Pongo really good.
One question that’s come up a lot: Is Rumple going to sing?
KITSIS:For that, we’ll have to wait until the musical airs!
Read our postmortem with Rebecca Mader on Zelena’s sacrificehere.Once Upon a Timeairs Sundays at 8 p.m.