Meanings of singular genius in English

What singular genius introduced the horse-race into a crowded street, I am yet to learn.

Their valour recommended them to a valiant people, and their singular genius for intrigue took root in every soil.

A composer like Ludwig van Beethoven towers over others, but even that singular genius didn't come out of the blue.

Lally's innate strength when impersonating rural characters -and this was his singular genius -came from the sophistication of his personal background.

He was a man of energy, enthusiasm, and high ideals, was possessed of a singular genius for finance, and believed in a vigorous national government.

"No, no, he is no madman; he is only a singular genius, who knows the world, and snaps his fingers at it."