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.

The collection includes correspondence, photographs, genealogical data, diaries, programs, clippings, legal and financial papers, and memorabilia of Nelson P. Darling and his son Frank Nelson Darling. There are letters from Billie Burke, Anton Long, Gustav C. Luders, Leopold Stokowski, and Florenz Ziegfield.

Dawn Powell (1896-1965) was an American author of novels, plays, and short stories. The collection includes address books, appointment books, books, clippings, correspondence, diaries, ephemera, family materials, manuscripts, notes, notebooks, photographs, programs, research files, reviews, scrapbooks, sketches and drawings.

Letters and manuscripts of MacDowell. One group was written to Arthur P. Schmidt, his publisher during MacDowell's years as professor of music at Columbia University. These letters concern the publication and distribution of his compositions and his copyright difficulties with other firms, especially Brietkopf & Härtel. There are eight letters from MacDowell to the American pianist, composer, and pedagogue William Mason. This personal correspondence deals with such things as musical pieces dedicated by each man to the other. A diary and letter book belonging to Marian N. MacDowell (Mrs. Edward) contains draft copies of letters to Nicholas M. Butler and others relating to his controversial career at Columbia University. Also, photocopies of eight letters from the Mary Flagler Cary Music Collection at the Morgan Library. Among the numerous musical scores and sketches are his INDIAN SUITE and the SONATA TRAGICA. Also, two original drawings of MacDowell by Orlando Rowland; and correspondence, manuscripts, catalogs, and other materials relating to the MacDowell Exhibition at Columbia University in 1938.

George Hamlin (1868-1923) was an American tenor. His daughter, Anna (1900-1988), was a soprano and voice instructor. The George and Anna Hamlin papers, dating from 1868 to 1983, document the careers of both vocalists through clippings, diaries, autograph books, programs, publicity materials, scores, photographs, and correspondence.

Ulysses Kay (1917-1995) was a noted twentieth-century American composer. The collection includes audio reels, biographical materials, correspondence, diaries, phonograph records, photographs, programs, and scores.