{"value"=>"Includes letters from William J. McDaniel, Elliott Schwartz (under the auspices of the MacDowell Colony), Attilio Macero, Gordon Mock, Jr., Carl McKinley, Alan MacNeil, Colin McPhee, Ursula Mamlok, Patricia Marcus, Vernon Martin, Donal Martino, Roger Mason, the Master Singers, Karl Mauzey, Richard Maxfield, Jack Maxon, Jerome Margolis, Donald MacInnis, Charles Madden, and others."}