15 letters Ominous request from a teacher ... or a hint to the first words (and following letters!) of 17-, 26- and 43-Across Answer: SEEMEAFTERCLASS
15 letters Who quipped "God tells me how the music should sound, but you stand in the way" Answer: ARTUROTOSCANINI
15 letters Question asked regarding two red-carpet photos of those named in the starred clues? Answer: WHOWOREITBETTER
15 letters Immediately ... or where this puzzle's five shaded squares appear? Answer: ATTHEDROPOFAHAT