The default singing accent in pop music is American. And for a reason. Had Art Garfunkel sung 'Bright Eyes' in a South African accent, it would have been quite a different song. Instead of a requiem, a lament, a tribute to a life passed, it would have been more about the passing of wind... the disappointment of the brief flame created by setting light to a fart (for confirmation, please view the clip at http://www.tinybangtheories.com/2012/01/fart-imitating-life.html).
Best wishes,
Paul (Ed.)