Whiskey sours were very popular in Japan when I was there in the mid-'90s. One could order them in a wide variety of fruity flavors and florescent colors. My concoction, derived from The New York Bartender's Guide recipe, was not so dazzling visually but it was certainly sour! The blended whiskey and lemon juice are in 2:1 ratio with only a teaspoon of sugar syrup. Mind you, I like sour so I was not unhappy. Wife liked it, too.
Sours have been around a long time, the first known mention in a Waukesha, Wisconsin newspaper in 1870. Add egg white (yuck!) and it's a Boston Sour. Float red wine over the top and it's a New York Sour.