This is not rocket science.

George London, a classical singer, sings "Lord Randal," a folk song. Kathleen Ferrier, a classical singer, sings "Blow Ye Wind Southerly," a folk song.

Miracle of miracles!! George London and Kathleen Ferrier are still classical singers and "Lord Randal" and "Blow Ye Wind Southerly" are still folk songs.

Richard Dyer-Bennet, a classically trained singer and classic guitarist, sang mostly folk songs. The songs didn't change because he sang them. They remained folk songs. Dyer-Bennet himself did not claim to be a folk singer. In fact, he denied it. He billed himself as "the twentieth century minstrel," evoking the image of a self-accompanied travelling singer following an ancient tradition.

Don Firth