Day, who lives in Nottingham, says she hasn't sung much professionally, and her appearance Wednesday will be her first with an audience that size.
"I performed with the Jazz Caravan, a jazz band, one time," she said. "And then, I led worship at Second Presbyterian Church in Towson. Other than that, I haven't really performed a lot. So, a lot of this is very new to me."
Day, who says her favorite genre is "soul" music, says she started singing in church at age 5.
"I loved the little solos that I would get, and I think that's maybe when the diva started to come out," she said with a laugh.
Here's video of Day from Fox: