I have already mentioned Smithsonian Folkways music. The Library of Congress is another source. The LOC is different in their collection is archival. You put a specific musician in their search engine and it will bring up what they have. The LOC recording library goes back to the earliest days of Audio recording. So if you want to hear John Philip Sousa recorded 100 years ago the LOC is were you will find it. The stuff is a free download if you wish.
https://www.loc.gov/programs/nation...complete-national-recording-registry-listing/
https://www.loc.gov/programs/nation...complete-national-recording-registry-listing/