French people do know about US/UK singers but not about all of them. Usually, we also know about some from Canada, Italy, Spain, Germany... but in a lesser amount. No young people know about Sacha Distel now, Nicole and Papa are fictional characters created for UK advertising and totally unknown in France, Plastic Bertrand is Belgian -as was Jacques Brel. Our best known pop singer is Johnny Hallyday (doesn't sound French but it's an alias). Francis Cabrel is a man -from Toulouse with a nice Southern accent- and has been singing for 30 years. If you want to know more maybe you can check the "French pop singers" and "French singer-songwriters" pages on Wikipedia then search Google for their web site or any YouTube video.