I can only speak with authority about NYPL. It's not the fault of the
Music Division if nobody points them to unknown people and their archives.
Nobody there had heard of Joe Reisman (arranger for Patti Page and Henry
Mancini, among others) until his widow called up to say she wanted to
donate his scores, and the library took them gladly. Most of that
collection was actually fairly pedestrian, middle-of-the-road pop
arrangements from the 1940s to 60s, which I'm glad the library has.
Collections of lesser-known or unknown artists are and should be
collected, but people should be proactive and actively contact libraries
and archivists and TELL THEM about unknown artists and their collections.
Matt Snyder
Music Archivist
Wilson Processing Project
The New York Public Library