If you could travel anywhere right now, where would you go? Nearly a month ago, Grammy-nominated reggae, hip-hop, and alt-rock singer-songwriter Matisyahu kicked off his latest tour, “Hold the Fire,” named for his five-song EP released Feb. 2. But before that, the “One Day” and “King Without a Crown” singer, whose music digs deep into his Jewish roots and spirituality, was in Israel, where he made a music video at the site of the Supernova Sukkot Gathering — an open-air music festival where, on Oct. 7, members of Hamas attacked concertgoers, killing 364 and taking dozens of hostages. “The song...