"It's really dark and all about sex," the actress-singer, who plays Mina Murray in the show, told UPI in a recent phone interview.
"It's almost like playing someone whose subconscious takes over her. It's a whole different animal."
Errico said her recent stint in the Irish Repertory Theatre production of "Finian's Rainbow" helped keep her "spirit light," while she was preparing to play the object of Dracula's obsession.
"I just wanted to come at it with my instincts and just be real," she said. "Because it will sweep me up anyway and that's for sure, so I just don't want to explode."
Noting the musical is a "rock and roll" version of the Bram Stoker novel, Errico said: "I can really get into the power of the story. It's pretty strong. ... It's all about desire."
"Dracula: The Musical" opens Aug. 19.