REMOVE

1. Nitrate negatives
2. negative
3. Opera singers.
4. Genthe, Arnold
5. Library of Congress Prints a …
6. 1921 Feb. 1

WHAT

1. Nitrate negatives (1)
2. Opera singers. (1)
3. Photographs (1)
4. Portrait photographs (1)

WHO

1. Genthe, Arnold (1)
2. Library of Congress Print … (1)

WHEN

1. 1869-1942 (1)
2. 1921 (1)
3. 1921 Feb. 1 (1)