I was just going to mention Clarence Ashley and Gwen Foster, I see somebody has done that. They're definitely a crew to check out. Listening to Foster ought to be a prerequisite for playing harp. Here's an Ashley and Foster, "My Sweet Farmgirl" from 1932. honkingduck.com/rams/41d47f81e1d6f5f1813e8801b4636b94.ram