Brian was “the glue that held everything together,” recalls a family member in the first few minutes of “Masterjam.” To some it probably wasn’t a surprise, then, when things fell apart after he took his own life. Brian’s brother Jamie uses footage gathered during his time as the family’s unofficial historian to examine the circumstances of Brian’s passing, the deterioration of their parents, and the roles that music, prescription drugs, and mental illness have played in the collective life of the Curry family. Simply edited, delicately produced, and fiercely honest, “Masterjam” presents the challenges of American (and African-American) family life in a vulnerable and relatable way.