RE: Aside from the first two I don’t know who in the world the others are.
You don’t know Steven Tyler of Aerosmith and Country Superstar Martina McBride? These singers are probably as “old” or “older” then Celine and Jennifer.
No, I have never heard of either. I grew up in the 1950s and was there when rock 'n roll first appeared. In the mid-1960s I was a radio disk jockey and appreciative of singers of songs that had what we quaintly used to call "melody." That aspect of songs seemed to have died out somewhere in the late 1970s, so I quit listening.
As to country and western music, that too changed and not for the better. The disappeance of such instruments as the fiddle and the steel guitar, to be replaced by multiple drums and electric guitars, did the music no favor, so I quit listening to that, too.
The rock 'n roll music and C&W music that you grew up with bear little resemblance to the real thing. Or at least, what I consider to be the real thing.
Best regards,
OldPossum