Some other famous people that sing in English (as a Second language) are:
Ricky Martin (from Puerto Rico), M2M (famous Swedish/Norwegian? pop group), Paulina Rubio (Mexico), Sumi Jo (Korean), Abba, Ace of Base, The Cardigans (all Swedish).I'm sure there are more...
For my opening activity I am going to highlight famous people in my students' country (or any that my students are familiar with) that speak and use English in their career. Then for the main activity I am using the song "Whenever, Wherever" by Shakira. I am having the students do a jigsaw activity with her lyrics and then identify word meanings with clues. I'll have them answer some multiple choice questions about the singer and the song itself after briefing kids on the meaning (with pictures, etc.) You could have students try to write some short lyrics to the tune of the chorus or illustrate the song with pictures. Hope you can use this idea in your class.