Wire recordings, primarily of classical performances from the 1950s, recorded from radio broadcasts by Michael H. Baker. These recordings capture works by Beethoven, Brahms, Mozart, Bartok, Wagner, Verdi, Haydn and others, performed almost entirely by the New York Philharmonic Symphony Orchestra under the batons of Guido Cantelli, Bruno Walter, Arturo Toscanini, and Dmitri Mitropoulos. Soloists include Jascha Heifetz, Robert Cassadesus, Artur Rubinstein, and Gregor Piatigorsky. There are also three non-music recordings; the one regarding the Rosenberg case is a dub from a transcription disc of a radio play titled "They Must Not Die", produced by the San Francisco Labor Theatre for the Bay Area Committee to Save the Rosenbergs circa 1952 or 1953. Notations on the boxes are indistinct, with some erasure. Spelling has been corrected when known (many are spelled phonetically, as if jotted down from the radio). Different recordings of the same perfomances are known to have been released commercially, but none appear to be copies of published releases.