The singer Lily Allen was educated at an upper class school but she sings in a mock cockney (mockney) accent. So she sings like that- "dih-int" for didn't, that kind of thing. I thought it refreshing that she didn't adopt the standard "pop music" accent and sang in her own accent, then I found out it's not even her accent. But she's sold a lot of music singing that way so... more power to her, I guess.