I’ve gone a bit gaga over YouTube clips of a Swedish jazz singer named Monica Zetterlund. Here she is singing Some Other Time with the Bill Evans (!!!!!) trio.
It’s what I call Blond Jazz. It just has such a fascinating lack of affect or connection on the part of the singer that it really clears the way for the audience to project their own thoughts onto a huge blank canvas. For this sort of work, maybe it helps to sing in a language that’s foreign to you.