Also essential: a set of prosthetic teeth that clipped onto Zellweger's own (because, if we've learned anything from Bohemian Rhapsody and Fosse/Verdon , it's that sometimes fake teeth are a must for getting into character). Her vocal coach, Eric Vetro, told the New York Post that it was a challenge at first for Zellweger to adjust to singing while wearing the teeth, but eventually she warmed up to them: Zellweger told Vanity Fair that the false teeth even served as a security blanket during some of her live performances, which triggered very real stage fright.