The answer is "Not nearly enough!"

Seriously, it goes on. Commercial music from the 20's and 30's, as well as popularly recorded folk music from all eras, is played in back bedrooms, dens, and garages and in town squares and city halls within the bluegrass tradition.

My father, who did a lot to promote bluegrass music in NE Texas, is in bed now in his final days of a sudden illness. For two weeks he has been singing lines from a Tom Paxton song, "The Last Thing on My Mind". Several lines of the melody are different, and a word here or there. Some of his friends have learned it from him, as he learned it by listening to others. In another 50 years, there will be several different versions, because this is a song that captures people's imagination and lives on in their hearts long after the guitar is set down. (And lest you think my father is being too maudlin, the other one he alternates it with is "Salty Dog!" Yea buddy!