Sara Bareilles and Jessie Mueller perform "She Used to Be Mine" from "Waitress." "Celebrating 50 Years of Broadway's Best" premieres Friday, May 12 at 9/8c on PBS. [VID: ♪♪ Who gets hurt, but who learns how to toughen up ♪♪ ♪♪ When she's bruised and gets used by a man who can't love ♪♪ ♪♪ Then she'll get stuck and be scared Of the life that's inside her ♪♪ ♪♪ Growing stronger each day 'til it finally reminds her ♪♪ ♪♪ To fight just a little to bring back the fire in her eyes ♪♪ ♪♪ That's been go