If you talk also about classics or Sinatra, I could mention a belgian genius, Jacques Brel, and a French one, Serge Gainsbourg. In fact, Terry Jacks sings a couple of Brel songs ("Seasons in the sun" and "If you go away", as well as David Bowie with "Amsterdam") But there you should speak french to get the whole art of it. And I admit this isn´t very much "rock", it´s rather popular music.