"It was the tango that changed the world"

Flash back to 1921. Female moviegoers were entranced with such handsome athletic actors as Douglas Fairbanks, Richard Barthlemess and Wallace Reid. But nothing prepared them for Rudolph Valentino's performance that year in Rex Ingram's acclaimed "The Four Horsemen of the Apocalypse."

As Julio, the charming wastrel grandson of a wealthy Argentine landowner before World War I, the smoldering Italian actor commands the screen, especially when he is in a local Buenos Aires dive watching a man and woman tango. Dressed in gaucho pants and bolero hat, he catches the eye of the woman dancing. Julio swaggers over to the dancing couple and asks to break into the dance. The man brushes Julio off, only to have Julio strike the man and take over in the woman's arms. Valentino's intensity and ardor still permeate the screen nearly 90 years later.

"This film really put him on the map, so to speak," says Donna L. Hill, who runs a Valentino website (www.rudolph-valentino.com) and is author of the new book "Rudolph Valentino: The Silent Idol."

" 'The Sheik' that followed only compounded that and increased his star appeal," she says. "But this is one of the few cases in any Hollywood film where you literally watch a star being born on film. The minute he starts dancing the tango, the whole film changes."