I've just found this site so my post may show up as 'guest,' but I'm having a hard time determining the public domain status of certain prewar folk and blues material, specifically in a case like Alvin's record. Rangerover observed that "All the songs on it are in the public domain, but he does credit the songwriters where known." I interpreted the song credits to mean that those songs were exceptions to the public domain status of the material - that, for example, Willie McTell (or someone who recorded him) still holds the copyright to "Mama, Ain't Long For Day." Any thoughts on how to arrive at a more definitive answer on matters like this?

david h.