Broadway’s Waitress, by Sara Bareilles, has been running at the Brooks Atkinson since 2016. “What Baking Can Do” features the rare downward modulation, from Gb to F, at 0:52, made even more noteworthy by an ascending melody. Gb returns at 1:28, and the song returns to F at 2:58 and concludes there. Performed here by original cast member and Tony Winner Jessie Mueller.