You have to love the music and treat it with great responsibility, even when raping it completely. It doesn`t matter if you were doing a Beethowen melody, or a Rihanna tune. You have to find some new meaning for the lyrics, or underline it totally, and / or turn it all upside down with your approach to the song. Don`t just play your bluegrass versions, make some music and try to say something while at it. IMHO 