Vocal range refers to the spectrum of pitches that the human voice is capable of producing. Vocal types are the categories used to group those ranges into definitive classes. The limited nature of the human vocal tract, combined with the fact that humans generally don't employ their entire range when vocalizing, explains why the more pitches a voice is capable of generating, the rarer that voice is.
Voice Anatomy
The sounds we hear when people speak and sing are a byproduct of how the human vocal tract operates. Two sections of elastic mucous membrane called the vocal folds, also known informally as vocal cords or vocal chords, stretch horizontally over the trachea (windpipe) in the throat's larynx (voice box). The folds open to allow air from the trachea to pass between them during breathing, and they close together to block the airflow when you hold your breath.
Speech, singing and other vocal sounds--such as laughing and screaming--occur when the laryngeal muscles cause the vocal folds to vibrate, change length, and alter tension as air travels through the trachea. The process controls the loudness and pitch of the vocal sounds produced.
Voice Types
Human vocal ranges are measured in units called octaves. Although designations differ, octaves usually represent the seven-step interval between two musical notes of the same tone, where the notes are A, B, C, D, E, F and G.
Female voices are generally higher than those of men because of basic differences between the vocal tracts of the two genders. Men often have longer and heavier vocal folds, resulting in lower-pitched, deeper voices.
Female Ranges
The three common voice types for women, from highest to lowest pitched, are soprano, mezzo-soprano and contralto. Sopranos generally sing in the range of Middle C to high C two octaves above, and contraltos in the range of the F immediately below Middle C and the second F above Middle C. The mezzo-soprano range, the most frequently found voice type among women, falls in the middle of soprano and contralto and overlaps both ranges.
Male Ranges
The classification system for male voice types commonly includes four classes. In order from highest to lowest pitch, they are countertenor, tenor, baritone and bass. The corresponding approximate note ranges are G immediately above Middle C to F two octaves above Middle C for countertenors, C an octave below Middle C to C one octave above Middle C for tenors, the second G below Middle C to G immediately above Middle C for baritones, and the second E below Middle C to E immediately above Middle C for bass. Baritone is the most common male voice type. Countertenors often sing in falsetto, a vocal register marked by high pitch and vibrating of the innermost edges of the vocal folds.
Child Ranges
In addition to the seven voice types for adult men and women, there is an eighth category called treble that applies to children whose voices have not yet changed due to puberty. Because boys and girls both have similar high-pitched voices at that age, there is no need to distinguish the vocal type with an additional class based on gender. Treble ranges from Middle C to the second A above it.
