Can you be considered a good music artist if you can't really give good live performances on stage??

Named "most unique and beautiful woman" of the year previously, R & B sensation "Rihanna" is highly favored as one of the most dominating and competetive women in the music industry right now. But after a failed attempt to impersonate the late king of pop, Michael Jackson, doing the moonwalk during a live performance of "Please Don't Stop the Music", people are starting to question if Rihanna should stick to making albums and making albums only.