In a class for language teachers, I learned that the brain uses one side for singing, and the other for communicating. That's why Celine Dion can sound one way on stage but not as pleasant during an interview. This explains how Fat Albert speaks low and airy, but has great tone while serenading the benefits of staying in school. As an example, check out this video of Applegirl. It's sounds like she has a Korean accent, but totally loses it while singing.