The 2011 Grammy's opened with a special tribute to Aretha Franklin that included a quintet of musicians, Christina Aguilera, Jennifer Hudson, Florence + the Machine's Florence Welch, Martina McBride and Yolanda Adams. The performance started with a group rendition of "Natural Woman" followed by each artist performing an array of Aretha's greatest hits. Watch the entire performance below and be sure to catch Christina's solo!!