In 1941 Vorkapich collaborated with John Hoffman, another montage editor, on a short non-narrative 'pictorial fantasy', Moods of the Sea. You can see the whole film on Ubuweb and admire its smoothly flowing seascape footage, set to Felix Mendelssohn's Hebrides Overture. They call it 'an early example of American avant-garde and independent film' - but it's not avant-garde in a 'shock of the new' way... It's really beautifully done, with waves crashing, seals gliding and gulls taking flight in time to the music. There's also the purely visual pleasure in seething black and white wave forms, dark horizons, mountainous clouds, stark shadows and bright light picking out bubbles on the foam.
Vorkapich and Hoffman made a similar film in 1947, Forest Murmers, shot in Angeles National Forest and scored to the interlude from Wagner’s Siegfried. I don't think this is viewable anywhere online... but you can see a clip from the opera below. Usually in this sequence Siegfried is shown sitting alone under a linden-tree, waiting for a dragon to appear, with the forest murmuring sounds in his ears. The birds' songs attract his attention and he makes a pipe from a reed in a vane attempt to imitate them.