Clarkson reminds everyone exactly why she won American Idol.
UPDATE: After her touching performance, Clarkson's song "Piece By Piece" launched to No. 1 on the iTunes Top Songs chart. The album by the same name soared to No. 3.
The song cuts deep for Clarkson as it details her father's mistreatment of her during childhood, in relation to how she will raise her children differently with the love of a good man, husband Brandon Blackstock. Clarkson also addressed her troubled parents on her 2004 smash hit Because Of You.
Kelly won the talent search series first season ever, way back in 2002. Since then, she's become one of the most successful contestants, releasing seven albums and in 2011, became the only artist to win Best Pop Vocal Album Grammy award twice.