There are times when a film simply needs to be upfront about being didactic — and this dispatch from the early days of the AIDS epidemic is a classic of event-movie didacticism. Adapted from Randy Shilts’s history of the epidemic, And the Band Played On didn’t set out to be a major work of art, unlike its Broadway contemporary, Angels in America. Band was about making the case to America that AIDS mattered — that people who were dying from it mattered, that the hatred unleashed against those who had the disease mattered. The cast reads like a who’s who of Hollywood, including gay and lesbian actors Ian McKellen, Lily Tomlin and B.D. Wong. It’s not a triumph of filmmaking — like any fictionalized documentary, it takes some liberties with facts in order create heroes and villains — but it is an essential cinematic moment for gays and lesbians in America. The saddest thing, in retrospect, is how many of the lessons it wanted to teach have yet to be learned.