Passaggio is a term used in classical singing to describe the transition area between the vocal registers. The passaggi (plural) of the voice lie between the different vocal registers, such as the chest voice, where any singer can produce a powerful sound, the middle voice, and the head voice, where a powerful and resonant sound is accessible, but usually only through vocal training. The historic Italian school of singing describes a primo passaggio and a secondo passaggio connected through a zona di passaggio in the male voice and the a primo passaggio and secondo passaggio in the female voice. A major goal of classical voice training in classical styles is to maintain an even timbre throughout the passaggio. Through proper training, it is possible to produce a resonant and powerful sound.
One cannot adequately discuss the vocal passaggio without having a basic understanding of the different vocal registers. In his book The Principles of Voice Production, Ingo Titze states, "The term register has been used to describe perceptually distinct regions of vocal quality that can be maintained over some ranges of pitch and loudness." When discussing vocal registration, it is important to note that discrepancies in terminology exist between different fields of vocal study, such as teachers and singers, researchers, and clinicians. As Marilee David points out, "Voice scientists see registration primarily as acoustic events." For singers, it is more common to explain registration events based on the physical sensations they feel when singing. Titze also explains that there are discrepancies in the terminology used to talk about vocal registration between speech pathologists and singing teachers. Since this article discusses the passaggio, which is a term used by classical singers, the registers will be discussed as they are in the field of singing rather than speech pathology and science.
Most voices can be divided roughly into three main registers.
All voice types, male and female, have these three main registers. The registers are named for the area in which the singer feels the vibration of the tone in the body. The chest register, more commonly referred to as the chest voice, is the lowest of the registers. When singing in the chest voice the singer feels sympathetic vibration in the chest. This is the register that people most commonly use while speaking. The middle voice falls in-between the chest voice and head voice. The head register, or the head voice, is the highest of the main vocal registers. When singing in the head voice, the singer may feel sympathetic vibration occurring in the face or another part of the head. Where these registers lie in the voice is dependent on sex and the voice type within each sex.