Their first Broadway musical was "Once on This Island," in 1990, which transferred from Off-Broadway's Playwrights Horizons. The musical was nominated for 8 Tony Awards including Best Musical, Best Book and Best Score. The London production of the show won the Olivier Award (London's Tony) for Best Musical in 1995. The show was later revived on Broadway in an immersive production at Circle in the Square in December 2017, where it was again nominated for 8 Tony Awards, winning for Best Revival of a Musical. The cast recording of the revival was nominated for the Grammy in 2019. It was Flaherty's first Grammy nomination as a Producer.