The phrase canto do galo is Portuguese for the crow of a rooster, and this clip is simply a recording of that familiar farmyard call rather than a line from a film or show. Rooster crows have long been used in cartoons, radio and video to mark sunrise, and the same shorthand carried over to memes, edits and soundboards. Because the sound needs no translation, it works in Brazilian and Portuguese videos as well as English ones, and it remains a quick way to say morning has arrived.