Did you know that the University of Massachusetts has started a Hip-Hop Archive? If you want to learn more about the effort to preserve the history of this music, or have unique or original materials related to Hip-Hop, swing by Bonsignore Hall at the Charlotte & William Bloomberg Medford Public Library and connect with the archive. The program will begin with a performance by the Boston Hip-Hop trio T.D.S Mob at 2:15 p.m. At 3:15 p.m., there will be a presentation on the Hip-Hop Archive and how you can contribute photos and stories, followed by a question-and-answer session at 4 p.m.