Briefe von Schönberg an M
| Empfänger | Firma |
| Maggio Mus Fior | |
| Mamon High School | |
| Manning, Maxwell & Moore, Inc | |
| Max Hesses Verlag | |
| Mercurbank | |
| Merkur AG | |
| Microstat Co. of Cal | |
| Minky's Stores | |
| Möbelfabrik WEHAKA | |
| Mödling, Allgemeine Gasgesellschaft | |
| Mödling, Bezirksgericht | |
| Mödling, Bezirkssteuerbehörde | |
| Mödling, Mietamt | |
| Mödling, Postamt | |
| Monteveritá | |
| Montreux, Postamt | |
| Mrs. Chabaneau R & E, Papier en gros | |
| MusBlätter Anbruch | |
| Music Printing & Photoprinting Company | |
| Musicians' International Dir | |
| Musikalienhandlung Jost | |
| Musikinstrumentenmacher Hozenauer | |
| MacAgy, Douglas | Cal Sch of Fine Arts |
| MacAgy, Douglas | SF Art Assn |
| Macdonald, Frank | |
| Machlis, Joseph | |
| Maclise, D.G. | UCLA |
| MacNeal, Vere | Texas State Col f Women |
| Mäurer, Gustav | Österr Mus- u Sangesbund |
| Magnin, Edgar F. | |
| Mahler, Alma | |
| Mahler, Fritz | Erie Philharmonic Soc |
| Mahler, Gustav | |
| Mainardi, Enrico | Acc Santa Cecilia |
| Maiweg, [?] | Duisburg |
| Malipiero, Gian Francesco | |
| Malipiero, Riccardo | |
| Malkin, Joseph | Malkin Conservatory |
| Mallachow, Agathe | |
| Mandl, Erich | |
| Manfred, D. | |
| Mangold, F.R. | Black Mountain Col |
| Mann, Heinrich | |
| Mann, Klaus | U.S. Army |
| Mann, Robert | |
| Mann, Thomas | |
| Marie[?] | |
| Marinus, HGH | |
| Markévitch, Zoia | |
| Marks, Herbert E. | Edward B. Marks Mus Corp |
| Marschalk, Max | Dreililien Verlag |
| Martens, Heinrich | |
| Martet, Jacques | Banque de France |
| Martone, Elizabeth | Columbia |
| Marwitz, [?] | |
| Marx, Josef | |
| Marx, Rudolf | |
| Mascolo, Dionys | Lib NRF Gallimard |
| Mason, Marilyn | Univ of Michigan |
| Mauck, Erich | |
| Maury, Lowndes | |
| Mayer-Serra, Otto | |
| Mayfield, John S. | |
| Mazur, Harry | |
| McBride, Charles | |
| McClung, C.M., Jr. | |
| McCormick, Katharyn D. | |
| McCormick, Ken | Doubleday |
| McFarland, Frances | U.S. Fed Works Agcy |
| McInerney, M.N. | Prentice-Hall, Inc |
| McKay, Francis Howard | |
| McKelvey, Raymond G. | Sou Cal Cncl of Inter-Am Aff |
| McKeon, Richard P. | UNESCO |
| McManus, George S. | Wesleyan University |
| McNamara, Daniel L. | ASCAP |
| McNaughton, Patton C. | UCLA |
| Melzer, Eugene C. | |
| Menasce, Jacques de | |
| Mendel, Arthur | |
| Mengelberg, C. Rudolf | |
| Mengelberg, Tilly | |
| Mengelberg, Willem | Concertgebouw |
| Merbach, Paul Alfred | |
| Merritt, A. Tillman | Harvard University |
| Meyer, Leonard B. | |
| Meyer, Wilhelm | |
| Michelson, Henriette | |
| Middleton, George | U.S. Dep of Justice |
| Miles, Russell H. | Univ of Illinois |
| Milewsky, Kurt | |
| Milke, Otto | Wäschereibetrieb |
| Miller, Calvin H. | |
| Mills, Rodney | |
| Milton[?], Seymour S. | |
| Mitropoulos, Dimitri | Minneapolis SO |
| Mitropoulos, Dimitri | New York Phil |
| Mitropoulos, Dimitri | Symphony Notes |
| Moe, Henry Allen | Guggenheim Foundation |
| Moenck, Johannes | |
| Mohr, Ernst | Neue Schweiz MusGes |
| Moll, Carl | |
| Moll, Leopold | Reichsanstalt für Mutter |
| Moller, Alice | |
| Moller, Hans | |
| Molnar, Ferenc | Stanford University |
| Monteux, Pierre | SF Symphony |
| Moore, Douglas | Columbia University |
| Moore, Douglas | League of Composers |
| Moore, Douglas | Nat Inst Arts & Letters |
| Moore, R. M. | Continental Securities Co |
| Moore, [?] | UCLA |
| Morse, Rose | Philosophical Lib |
| Morton, Lawrence | |
| Mottram, H.M. | Milwaukee Friends of Mus |
| Moulaert, P. | Éditions mus A.A. Stols |
| Moulton, Dorothy | |
| Müller, Friedrich | |
| Munch, Charles | Boston SO |
| Munro, Thomas | Am Soc for Aesthetics |
| Munro, Thomas | Cleveland Museum of Art |
| Murphy, James P.J. | |
| Murray, Josephine | Cal-Wstn Mus Educ Conf |
| Myers, Rollo H. | ISCM |
| Myron, Paul V. | U.S. Dep of Justice |
