I've always sung Irish & American songs in my own Geordie accent (the way I speak) and mostly got away with it I think?

I can't sing 'Another Saturday Night' in Sam Cooke's accent, but it's a great song, & adapt the words to suit setting an example one day the environment- is that OK- I don't care really

I have a lovely memory of Forster Charlton, legendary Geordie fiddler and Northumbrian piper demonstrating this view in a rare burst of the 1943 song 'You'll Never Know'    as follows....

'Ye'll nivvor knaa jist how much aa luv ye
Ye'll nivvor knaa jist how much aa care   
And if aa tried aa still cuddernt hide me luv for ye
Shuarly ye knaa cos hevvent aa telt ye so
A million an' mair times .....

          (you can do the rest!)

   
sing as you speak - yes...