Ron, I am not familiar with Bruce Springsteens music.You referred to other musicians, So I thought you were referring to embellishment, improvisation of melody of the tuneETC .Which is certainly different from Sharps bowdlerisation of the Keeper.
Malcolm Douglas,Cecil Sharp bowdlerised the song the Keeper, My comments are not uninformed.CECILSHARPS work was important , So was BARING GOULD ,LUCY BROADWOOD, FRANK KIDSON, Mary Neal, Peter Kennedy, Seamus Ennis,Sean O Boyle. Sadly the first four,have not had the same recognition as SHARP ,.
Iwould define the collections of Sharp, Broadwood, Baring Gould, Kidson,As traditional music, thats quite a lot of songs to start with., plus Hugills collection of shanties, plus the Child ballads.