This is a colorized silent short film by Starewicz, the famous master of stop-motion animation. Produced in France by Pathé, it was originally called La voix du rossignol.
IMDb summary: A fairy-tale-like telling of why the nightingale only sings at night. A young girl who has caught a nightingale dreams about the nightingale and its mate, and comes to realize that birds are not made to be captive but free. In return for its freedom, the nightingale loans the child its voice for use in the daytime, which is why nightingales only sing at night.
IMDb link: http://www.imdb.com/title/tt0014584/
Thank you so much for uploading this lovely lovely film. I am having a testing day and this lightens the sorrow!
inner5pace 1 year ago