Pop acts on television this week include Enrique Iglesias, who again appears on ‘How I Met Your Mother’ on Monday; Mandi Perkins, who appears on the season premiere of ‘Girlfriends’ on CW on Monday, performing ‘Who I Am’ and ‘Why Pretend’ in a concert scene; Tori Amos, who performs on ‘The Tonight Show with Jay Leno’ on Monday; Annie Lennox, who performs on ‘Today’ on Tuesday, ‘The View’ on Thursday and ‘The Tonight Show’ on Friday; Train singer Pat Monahan, who performs on ‘The Tonight Show’ on Tuesday, ‘The Late Late Show with Craig Ferguson’ on Thursday and ‘Last Call with Carson Daly’ on Friday; Steve Bertrand, who performs on ‘The Late Late Show’ on Tuesday; Janet Jackson, who visits ‘The Oprah Winfrey Show’ on Wednesday; and Sinead O’Connor, who reveals for the first time on television her struggle with bipolar disorder on ‘The Oprah Winfrey Show’ on Thursday.