The two will be performing "There Once Was a Man."
In the show, Connick (composer of Broadway's Thou Shalt Not) is Sid Sorokin and O'Hara (Tony nominee for The Light in the Piazza) is Babe Williams, the lovesick management and labor chiefs, respectively, at the musical's Sleep-Tite Pajama Factory in Cedar Rapids, Iowa.
Opening night is Feb. 23.