Papers, letters, memoranda, memorabilia, and manuscript music scores assembled by and related to the life and musical activities of Anton Seidl. The collection includes many letters from Cosima Wagner and her children addressed to Anton Seidl and his wife, the opera singer Auguste Kraus Seidl. There are also letters from Lilli Lehman, Edvard Grieg, Antonin Dvorak, Bronislaw Hubermann, Carl Goldmark, Maud Powell, Marianne Brandt, Felix Weingartner, Lyman Abbott, and many others. The letters are chiefly concerned with musical performances, composition, and related affairs. There are journals, diaries, and memoranda in Seidl's hand, as well as photographs and clippings relating to his conducting career. Also, twenty-seven manuscript scores of Seidl's orchestrations of various works.

Correspondence, manuscripts, documents, photographs, and printed materials documenting the life of Harold Melvin Triggs. The correspondence is primarily personal and from other musicians. There are concert prograpms from various points in Trigg's career and photographs primarily of Triggs and Vera Brodsky. There are manuscript and printed scores mainly of piano music but of some orchestral music as well. There is also a scrap book made by Triggs as a small child

Correspondence, manuscripts, papers, essays, etc. relating to Berlioz, and 19th century arts and literature. The correspondence includes original Berlioz letters and over 200 copies of letters relating to Berlioz and the romantic era, written by musicians, critics, historians, and literateurs of the past century. There are many photostats of letters and manuscripts obtained from the principal libraries of the world which hold original Berlioz material. The collection includes much printed material in the form of music scores, published letters, essays, clippings, biographies, music and book catalogues, program notes, and playbills.