Birds are able to produce a great diversity of sounds. They vocalize with a specific vocal organ, the syrinx, producing the primary vibration. However, it is not fully understood how the produced sound is filtered afterward by the vocal tract (trachea, upper part of the esophagus, oral cavity, and beak). We know that in songbirds, motions of the vocal tract help modulate the sound. When producing low pitch sounds, the throat and breast area expend visually, and the beak stays fairly closed. Conversely, while making high pitch sounds, the neck elongates and the beak opens widely. We hypothesize that all birds can filter the sound by changing the length and volume of their vocal tract. To determine how the different parts of the vocal tract modulate sound in songbird and non-songbird species, we filmed birds vocalizing with light cameras and synchronously recorded their sound with microphones to quantify the motions of the beak, neck, and pouch, while birds produced different sounds. Our results suggest a correlation between vocal pitch and the motions of the beak, neck, and pouch, supporting previous observations. This work shows that the complexity of bird vocalizations is not only related to the syrinx, but also to the entire upper vocal tract, which provides elements to better understand birdsong functional morphology.