Who is this American singer that is listed in Guinness World Records as having "the best selling album by a teenage solo artist" And, became as an international pop culture icon after just launching her career. She is also known for her iconic performances and music videos,...she is one of the most controversial and successful female vocalists in 21st century. She is a part of one of the biggest artists in walk of fame. Her music best describes the contrast between innocence and darkness which causes to create a perfect music spectacle.?