I thought about this one for a while. Lots of possible categories/themes passed through my head.
Finally, in trying to make it as simple as possible, it came to me. I've always been partial to the sound of a woman singing lead. And it does leave a huge amount of territory to explore, as I said in my description earlier, when I announced it:
Much in the same way that any three non-collinear points will define a plane. So Maria Callas, Bessie Smith, and the McGarrigle sisters would all both qualify, and help extend the plane to infinity in all directions.
And as for the number:
I’m leaving quantity pretty open, let’s say six to ten links as an approach. More if you like, keep it to six as a minimum, though, please.
That ought to leave a lot of room for just about anyone to find some tracks they like, and want to share.
Have at it...