The site Juneberry78s.com has created a great old-time country listening room with over 75 old 78 rpm records available in MP3 form. There are some terrific recordings there by folks like Riley Puckett, Dick Justics, Frank Hutchison, the Skillet lickers, and many more.

http://www.juneberry78s.com/sounds/ListenToOTCountry.php