How on earth can you decide to only sing songs in yout native dialect? There are a hell of a lot of amazing songs out there that you've just decided never to sing. I've a fairly BBC accent and I'll sing Irish songs, scottish songs, English, cornish, welsh, french, italian, breton... If I had to stick to my dialect I doubt I'd find a single folksong I could sing.

At the end of the day, if you can make a decent performance of it, who cares what your accent sounds like? If the audience understand and you can put a bit of emotion into it, who is honestly going to object?

Also, I find that my accent does change very slightly anyway. I suppose if you learn your songs from a person or recording, you'll tend to imitate them a bit subconsciously. This doesn't mean I try to put on a broad scots accent to sing a song by burns. That'd just sound crap. At the same time, I'm not going to deform the work of a great poet just because I think 'gang' or 'lassies' aren't correct. (Actually, thinking about it, my version of green grow the rushes came from an irish singer and probably doesn't sound remotely scottish.)

Anyway that's my contribution. Sorry for barging in- I couldn't resist.