joethejohnston:

Haha, its funny because every time I hear that part I think its Rebecca singing! But it is really Zach Callison’s voice, it just happens to sound like it does. One thing you may not know is that very often the songs are cobbled together from multiple takes. The voice actors will sing the songs all the way through several times, and also individual parts and we’ll edit together the best runs to get the final version.