Christina Aguilera

The provided news articles do not contain any information about Christina Aguilera. The articles primarily focus on Lady Gaga's impact on pop music, Mariah Carey's participation in the Winter Olympics opening ceremony, and other related events. Therefore, it is impossible to provide a summary about Christina Aguilera based solely on the given context. The articles mention Lady Gaga's rise to fame and her influence on pop culture, as well as Mariah Carey's involvement in the Winter Olympics alongside Andrea Bocelli. However, Christina Aguilera is not mentioned in any of the articles.