In the early 1930s, experiments with "Sound Montage" constructed films based on musical rules by perfectly synchronizing cutting and music. Citizen Kane used music by Bernard Herrmann. Films expressed time and rhythm through camera movements like pans, tracks, and tilts. The documentary "New Earth" represented machinery with natural sounds and men with music, with a score by Hanns Eisler that was innovative for its time. The avant-garde film "L'Idee" had an imaginative score by Arthur Honegger using an electronic ondes martenot instrument. Other notable avant-garde documentary films of the era included "Le sang d'un poete", "Zero de Conduite", and "