The Brave hitmaker has earned rave reviews for her work on new musical Waitress, which she wrote the music and lyrics for.
During a concert at New York City's City Center on Thursday night (06Nov15) featuring songs from the show, Bareilles revealed Waitress is actually the second musical she's written - but the first one didn't quite find the same success as her current show.
Telling the audience she and the Sugarland star came up with the idea while on tour together a few years ago, Bareilles said, "We started writing a musical together called Lesbians! And we wrote five songs."
"One of them is called Lesbians on Parade, and it was inspired by the Lilith Fair," she added, referring to the popular mid-1990s music festival which only featured female musicians.
"It was my first attempt at writing a musical and that oddly enough didn't go so well," she joked. "It was truly a blessed journey for me."
Waitress, based on the 2007 film of the same name, starring Keri Russell, will premiere on Broadway at the Brooks Atkinson Theatre in March (15), starring Tony winner Jessie Mueller.