Vocal range is the measure of the breadth of pitches that a human voice can phonate. Although the study of vocal range has little practical application in terms of speech, it is a topic of study within linguistics, phonetics, and speech and language pathology, particularly in relation to the study of tonal languages and certain types of vocal disorders. However, the most common application of the term "vocal range" is within the context of singing, where it is used as one of the major defining characteristics for classifying singing voices into groups known as voice types.
Singing and the definition of vocal range
While the broadest definition of vocal range is simply the span from the lowest to the highest note a particular voice can produce, this broad definition is often not what is meant when "vocal range" is discussed in the context of singing. Vocal pedagogists tend to define the vocal range as the total span of "musically useful" pitches that a singer can produce. This is because some of the notes a voice can produce may not be considered usable by the singer within performance for various reasons. For example, within opera all singers must project over an orchestra without the aid of a microphone. An opera singer would therefore only be able to include the notes that they are able to adequately project over an orchestra within his or her vocal range. In contrast, a pop artist could include notes that could be heard with the aid of a microphone.
Another factor to consider is the use of different forms of vocal production. The human voice is capable of producing sounds using different physiological processes within the larynx. These different forms of voice production are known as vocal registers. While the exact number and definition of vocal registers is a controversial topic within the field of singing, the sciences identify only four registers: the whistle register, the falsetto register, the modal register, and the vocal fry register. Typically only the usable pitches within the modal register—the register used in normal speech and most singing—are included when determining singers' vocal ranges. There are, however, exceptions. In opera for example countertenors often use falsetto and coloratura sopranos frequently use the whistle register while in popular music male doo-wop singers might regularly use falsetto pitches; notes from these registers would therefore be included in the vocal ranges of these voices.
Vocal range and voice classification
Vocal range plays such an important role in classifying singing voices into voice types that sometimes the two terms are confused with one another. A voice type is a particular kind of human singing voice perceived as having certain identifying qualities or characteristics; vocal range being only one of those characteristics. Other factors are vocal weight, vocal tessitura, vocal timbre, vocal transition points, physical characteristics, speech level, scientific testing, and vocal registration. All of these factors combined are used to categorize a singer's voice into a particular kind of singing voice or voice type.
The discipline of voice classification developed within European classical music and is not generally applicable to other forms of singing. Voice classification is often used within opera to associate possible roles with potential voices. Several different voice classification systems are available to identify voice types, including the German Fach system and the choral music system among many others; no system is universally applied or accepted. Most of the voice types identified by such systems, however, are sub-types that fall under seven different major voice categories that are for the most part acknowledged across all of the major voice classification systems. Women are typically divided into three main groups: soprano, mezzo-soprano, and contralto. Men are usually divided into four main groups: countertenor, tenor, baritone, and bass. When considering the pre-pubescent voices of children an eighth term, treble, can be applied. Within each of these major categories there are several sub-categories that identify specific vocal qualities like coloratura facility and vocal weight to differentiate between voices.
Vocal range itself cannot determine a singer's voice type. While each voice type does have a general vocal range associated with it, human singing voices may possess vocal ranges that encompass more than one voice type or are in between the typical ranges of two voice types. Therefore, voice teachers use vocal range as only one factor among many in classifying a singer's voice. More important than range in voice classification is tessitura, or where the voice is most comfortable singing, and vocal timbre, or the characteristic sound of the singing voice. For example, a female singer may have a vocal range that encompasses the high notes of a mezzo-soprano and the low notes of a soprano. A voice teacher would therefore look to see whether or not the singer were more comfortable singing up higher or singing lower. If the singer were more comfortable singing higher, then the teacher would probably classify her as a soprano and if the singer were more comfortable singing lower, then he would probably classify her as a mezzo-soprano. The teacher would also listen to the sound of the voice. Sopranos tend to have a lighter and less rich vocal sound than a mezzo-soprano. A voice teacher, however, would never classify a singer in more than one voice type, regardless of the size of the vocal range of the singer.
The following are the general vocal ranges associated with each voice type using scientific pitch notation where middle C is written as C4. Some singers within these voice types may be able to sing somewhat higher or lower: