I had skipped this thread because I seldom sing Irish songs. But the concept seems to have broadened beyond Irish songs so I will step in with my own accent.

I think some songs require an accent. The accent helps to "place" the songs in their context. Someone mentioned Robert Burns without any Scottish inflections. It won't "sound right".

I sing songs of the common people and my pronunciation is less "proper American English" when I sing. It is possible to go overboard with this and truly become a parody when the object is to serve the song.

When I sing the blues I frequently drop my "g's" and may use the incorrect grammar that is in the song. I am trying to be faithful to the music. When I sing Stephen Foster, though, I "clean" up his writing because it was not "his" accent he was writing, but his own interpretation of an accent. I don't sing "oughta been on the river nineteen and te." Notice it is not "ribber" (and doesn't sound like "ribber" on Lomax's tapes. Notice also it is not "Ought to have been on the river in nineteen and ten".

Roger in Baltimore