I definitely sing with an American accent, Midwestern regional variant.

Most of the time.

Likely cause that's where I come from.

However, there are times when bits of other accents creep in. I don't think anyone has accused me of a Mid-Atlantic sound, but as Backwoodman mentioned earlier, "that accents are absorbed by performers by a sort of process of auditory osmosis" I am also most certainly of that ilk.

I can't "do" accents, and also tend to sadly agree I can't do justice to a song, no matter how much I love it, if it's in a fairly thick accent. Yet when I go places, I find myself unconsciously absorbing the linguistic quirks of where ever I am & the longer there, the longer it takes to wear off when I'm home. Two weeks in Wyoming had me talking like a cowgirl for about 2 weeks back in Cleveland.

Singing with an English or Irish or Scottish flavor comes out in some of the songs I've absorbed from particular singers, and the kind of phrasing and stress and musicality of language that are part of how the words come out owe much to them. When I have the chance, I will introduce a song with "I learned this from the singing of..." I do not TRY to sound like my source, or "put on" an accent, but as Jim mentioned, there are words and phrases that need to be part of some songs where saying them in one's own voice is the way to go. But sometimes that may sound like there's a foreign accent creeping it, and you take hell for it from someone who just wants to take umbrage. I shall never forget, as a wee girl in first grade in Cleveland, explaining that my aunt was my primary caregiver. I said "aunt" in what I later learned was a Philly Mainline accent, where my aunt was from."You mean your ANNNNT?" sez the nun in a harsh, flat Midwestern voice, "don't put on airs here, missy!"

Those who put on strong accents unsuccessfully and sound fake are likely to have other bad habits in what they sing. I try to behave myself.

Joanne in Cleveland