The Papers of Stanley Dance and Helen Oakley Dance are an important resource for the study of 20th-century jazz history in the United States. Of particular interest are transcripts from interviews with a number of jazz musicians, a large selection of photographs, and sound recordings – many of which are unique. Most – but not all – of the material having to do with Earl Hines and Duke Ellington can be found in their respective series. Researchers are advised to examine other series for additional material.