I looked for this information today and struck out. Hoping I'm able to help someone else:

Row A in the mezzanine at the Wang Theatre in Boston overlaps Row L on the floor, but at concerts, the orchestra pit is filled with 7 extra rows so you are actually 19 rows back from the stage, making you equivalent to being above row S.

Also, no kids should sit in row A because the railing is as tall as a dresser.