Here you'll find a large collection of Rags in MIDI format which would often suit the mood of general action scenes in silent movies, but not chase scenes, being tied to railroad tracks, or scenes of great pathos.

In the distant past I have seen 'Classical' music collections on the Web that have been tagged as candidates for silent movie use. As I recall one particular composer was very popular, but neither my memory nor my knowledge are very useful on that subject.

Regards, John