Those of us familiar with unmedicated labors are used to hearing women vocalize during contractions. We often talk about women's "birth songs," although frankly that phrase is often a euphemism for sounds that are more like a bellowing cow or roaring lion or some scary monster from a b-grade science fiction movie. Eric described my pushing vocalizations as "coming from the belly of the best."
But...sometimes women actually do sing--and I mean SING--during labor. Bellies and Babies recently posted a video of her friend singing during her labor, accompanied by her husband on a guitar. It's beautiful. Supposedly she had a couple contractions during the video, but I had a hard time telling when!
Singing during labor makes a lot of sense. It makes us take nice, deep abdominal breaths, and then sloooooowly release the air as we sing. It also ensures that we keep the mouth, throat, and neck relaxed, which is great for keeping the pelvic area loose as well.