Directions Unit- Editing 2

Soviet film makers of the 1920s like Kuleshov, Pudovkin and Sergei Eisenstein all were founding fathers of montage, although it is argued that Eisenstein defined lent status to what he called "intellectual montage".

Montage means to assemble. Although Lev Kuleshov was the first to experiment with Montage, Eisenstein argued that the collision between two adjoining images creates a third meaning. He said editing should make people think, not just what they see. Eisenstein classified montage into metric, rhythmic tonal and over tonal methods.
Metric montage. In metric montage, shots are joined together according to their length, with absolute length of the piece already determined. Thus, tension is created by shortening each shot while preserving the original proportions of the formula. This can be seen in chase sequences. 

Rhythmic montage. While in metric montage, the content is determined by the absolute length of the sequence, in rhythmic montage, the action within the frame is given as much weight as the actual physical length of each shot. The rhythm of the montage can therefore conflict with the rhythm of the movement within the frame, thus generating tension.  

Tonal montage. The emotional tone of a sequence directs this montage. Consider the example of a city that has just been bombarded by a series of missiles. This sequence of rapid cutting is in total contrast to the montage that follows of smoke from houses, a baby crying, a collapsed part of a heritage building, a women wailing, volunteers helping relative identify bodies etc. With it's slower pace, a tonal montage acts as a bridge that functions not only to cool the violence of the preceding missile attacks but also prepare for retaliation.  

Over-tonal montage. It is a combination of all the three types of montage discussed above. Over-tonal montage required that more than one type of montage occur simultaneously, thus creating a montage construction in which the methods exist in a relationship and may conflict with one another.

In this film they give some background to the Montage theory, they use different terms to the ones I have used above such as "Rhythmic" refers to "Hollywood" in this film.