An African American singer who appeared in concert at our church specializes in spirituals (lucky me!), and we discussed the practice of singing/not singing in dialect at least as far as "concert song" style. He explained that the classically-trained singers' approach has long been that when the dialect provides a consonant that helps the clarity of the sound produced-- the overall singing diction-- one might choose the dialect word over the more current pronunciation. But, he said, and I agree with this, one does not use dialect to imitate, even if attempting to be faithful to history-- the songs are meant to be sung in the idiom of the singer, as were the originals. These are my paraphrases-- he had the technical terms at hand, and I don't, at the moment. But that was his take on the question of dialect.

~S~