My purpose is to discuss simply, intelligibly, yet from a scientific point of view, the sensations known to us in singing, and exactly ascertained in my experience, by the expressions "singing open," "covered," "dark," "nasal," "in the head," or "in the neck," "forward," or "back." These expressions correspond to our sensations in singing; but they are unintelligible as long as the causes of those sensations are unknown, and everybody has a different idea of them. Many singers try their whole lives long to produce them and never succeed.