When not in 60s-70s classic rock, my fave shop music is Patsy. Her voice really matured the last few years. Such a tragedy that she is gone.
Karen Carpenter also had the effortless range and depth that Patsy had.
There are many others, I'm sure.
It is a shame that most singers these days feel obliged to scream. My wife watches The Voice, et al and I continually complain about singers trying to do something (via screaming) that they are simply not able to do.