Will Grumpy and the rest of Once Upon a Time‘s dwarfs finally sing about whistling while they work? Will erstwhile cricket Dr. Archie Hopper let loose with a tune about wishing upon a star?

“Be prepared” (as Scar might croon), because such melodic mysteries might be addressed during Season 6. TVLine has learned that the fantastical, fairy tale-themed ABC series is currently planning a musical episode, to air sometime this spring. And to that end, some cast members are actively brushing up on their vocal skills. Winter TV Preview: Returning Favorites

Following TVLine’s report, Once creators Adam Horowitz and Eddy Kitsis confirmed the musical during a Feb. 2 appearance at the Atlanta aTVFest.

Having weaved in characters from Frozen, The Little Mermaid, Aladdin and other musical Disney features over the years, talk of Once cuing up a musical episode has always brewed, with series cocreator Eddy Kitsis saying as recently as the 2015 Comic-Con, “It would be great to do a musical episode, [but] I don’t know even know where to begin.”

Well, it would seem that the show bosses figured that one out.

As for who all would step up to the proverbial mic, “We all sing,” Once lead Jennifer Morrison told E! Online back in 2011 when asked about the possibility of a musical outing. “Josh Dallas, Ginny Goodwin, me…. I don’t know if Robert Carlyle sings; he probably does. I feel like we have a lot of musically inclined people in the cast. We’ll see!” Indeed.

Once, of course, won’t be the only musical lark in town this spring: The CW’s Supergirl/The Flash crossover will find the superfriends battling the Music Meister while breaking out in song, in a two-parter airing March 20-21.

Once Upon a Time resumes Season 6 on Sunday, March 5.

Want more scoop on Once, or for any other show? Email insideline@tvline.com and your question may be answered via Matt’s Inside Line.