Sergei Eisenstein's 1925 masterpiece, "Battleship Potemkin," is considered "avante garde" precisely because it was well-ahead of its time in several ways. In his depiction of a revolt by sailors returning from war in the Far East, Eisenstein employed techniques that were revolutionary in their application (no pun intended, by the way). His use of photography, editing and music all represented major innovations in the way films are made. The editing, in particular, has remained a highly respected component of the film that continues to inspire film students and directors today. Rather than employ a linear approach to his photography, Eisenstein used editing to show "reaction" shots interspersed with the action. Most memorable was the famous scene showing a baby carriage rolling down a staircase amidst the fighting and the horrified reactions intercut into the scene. That scene in particular has been copied and lampooned ever since.
While "Battleship Potemkin" appears almost comical today in its portrayal of brutal czarist soldiers and heroic revolutionaries, like any film of its time, it needs to be viewed in the proper historical context. Russia was emerging from a series of revolutions and was still engaged in a bloody civil war. The Bolshevik leaders wanted a film that would emotionally affect its audience and inspire greater revolutionary fervor in the public. "Battleship Potemkin," with its now-famous montages and use of classical music to evoke emotional responses from the audience, served its purpose admirably.