As is much discussed on this site, one of the most interesting aspects of music and musical culture is that it is temporal and incorporeal; it is one of music's greatest and worst qualities. So much can be lost when sounds are passed from generation to generation, and only in the tiniest recent sliver of human history have we been able to capture those sounds and preserve them, in direct and (if desired) unmediated ways through sound recording.
Early in the history of recording technology, a few pioneers realized the technology's importance for documenting and preserving musical and aural culture. Foremost among these early musicologists is Alan Lomax (also a field collector, folklorist, archivist, filmmaker, scholar, etc.), who recognized not just the immense value of folk music but of recording it, and began traveling to do so in the early 1930s. His contributions to our cultural history and preservation are enormous.
Amazingly, his entire archive is available online, free of charge. It is huge and amazing, and features recordings of concerts, social gatherings, worship services, street criers, interviews, and more. I had a hard time choosing even just a few samples to incite your curiosity.
This NPR piece is a great place to begin acquainting yourself with this veritable trove of music and people and the many delightful ways we use sound expressively.