Bareilles performed "She Used To Be Mine" from the new musical and also offered a tune from The Little Mermaid, which she often sings when something goes wrong in a live performance.
Watch the performances below as well as a discussion of the demands of writing a book.
"She Used to Be Mine"
Sara Bareilles Sings The Little Mermaid to Cover Up Mistakes
Sara Bareilles Wrote a Book for Bragging Rights