FORT GREENE Martin Luther King, Jr. Day is much more than just a wintry day off work. This weekend, BAM is celebrating the life of Dr. King by spotlighting musicians, artists and films that carry his peaceful message. The weekend is framed by an art exhibition, Picture the Dream, created by New York City Housing Authority residents under the age of thirteen and guided by graphic artist Cey Adams. It’s on view through the 17th at BAMCafé, where two musical artists will be playing in King’s honor: Ghanaian hip-hop artist Blitz the Ambassador on Friday, and Afrobeat/house “sonic healer” the Earthman Experience on Saturday. The main event takes place Monday at the opera house, where BAM, Marty Markowitz, and Medgar Evers College join forces to celebrate King’s life. This year’s keynote speaker, Walter Mosley, is best-known for his crime novels; he’ll be joined by legendary Brooklyn a cappella group the Persuasions and the Reverend Timothy Wright Memorial Choir of the Grace Tabernacle Christian Center C.O.G.I.C. A screening of Neshoba: The Price of Freedom, a documentary that examines the aftermath of the 1964 murders of three civil rights workers, closes out the tribute.