This year when Shavuos is Sunday night, when is it permitted to listen to music again?
Sunday morning for non-Mitzvah-related music. See here: https://asktherav.com/from-when-till-when-are-you-not-allowed-to-listen-to-music-3880/ As well as on page 12 of the Day-to-Day Shavuos guide. Sources: לכאו׳ יל״ע למ״ד לנהוג אבלות עד ערב שבועות…