Vocal range
Human voices may be classified according to their vocal range  the highest and lowest pitches that they can produce.

# Vocal range defined
The broadest definition of vocal range, given above, is simply the span from the highest to the lowest note a particular voice can produce. This broad definition, however, is quite often not the one meant when someone speaks of "vocal range." This is because some of the notes a voice can produce may not be considered "musically useful" for a particular purpose. For example, when speaking of the vocal range of a male opera singer, one usually excludes falsetto pitches, which are not used in most opera. A male doo-wop singer, on the other hand, might quite regularly deploy his falsetto pitches in performance and thus include them in determining his range.
For this reason, it is important to clearly define what is meant when discussing a vocal range. For example, one might say of a man that he has a two and one-half octave range in full voice and an additional one half octave in falsetto. Similarly, when discussing the range of a woman one might say that she has a "useful" two octave range with an additional major third on the bottom that is only audible with amplification. Unfortunately, there is no standardization in this nomenclature outside of classical unamplified singing.

# Vocal range in classical music
Vocal range is generally very important in classical music. In opera and solo classical music, two considerations are paramount in determining vocal range: consistency of timbre across the vocal range, and ability to project the pitches (that is, to be heard clearly over an orchestra without amplification). Of course, if any pitch cannot be properly projected, it is not considered part of the range. See voice type.
Choral music is somewhat less stringent than opera. In contrast to opera, the large number of voices that can be deployed in each group make it somewhat less important that each individual voice be flawlessly produced and completely audible. Thus, for example, choirs can often deploy notes that are lower than those that might be deployed in an operatic performance - no single member of the choir might be able to project such a low note individually, but taken together the note might be quite audible.
In much choral music the vocal ranges are often divided not into the three parts per sex as they are in operatic solo music but into only two parts per gender - Soprano, Alto, Tenor, Bass - or into four parts per sex - Soprano I, Soprano II, Alto I, Alto II, Tenor I, Tenor II, Bass I (or baritone), Bass II. For example see the Mass in B Minor. There is therefore some ambiguity in mapping the solo baritone voice defined in the three way solo system to the four way choral system.  Many high baritone soloists like Sherrill Milnes might have sung Second Tenor in a chorus, (usually not a preferred compromise) whereas other baritones such as Bryn Terfel might have sung First Bass. They would have had to choose one or the other as any baritone part is labeled in that manner.

# Classification of vocal range
Basic Operatic Ranges:
- Soprano: C4 - C6
- Mezzo-Soprano: A3 - A5
- Contralto: E3 - E5
- Tenor: C3 - C5
- Baritone: G2 - G4
- Bass: E2 - E4
Note: Depending upon the conductor's vocal exercises & observations, an individual may possess an extended range which may allow a shifting of choral sections.
Basic Choral ranges:
- Soprano: C4 - A5
- Mezzo-Soprano: A3 - F5
- Contralto: F3 - D5
- Tenor: B2 - G4
- Baritone: G2 - E4
- Bass/Basso: E2 - C4
A soprano who can sing higher than CTemplate:Music6 is known as a sopranino and a Bass  who can sing G1 or lower is known as a sub-bass singer or a basso profondo. However, many people will still call sopraninos sopranos and basso profondos basses/bassos.
Male falsetto and female flageolet register can extend the vocal range of a singer higher.
Males who possess high ranges or can project falsetto, are referred to as countertenors and possess ranges equivalent to those of the female ranges, alto, mezzo-soprano and soprano (a male soprano is specifically referred to as sopranist). Contraltos have been known to sing Tenor (although this is strongly discouraged, especially among younger contraltos), and occasionally men will sing in the upper three ranges.
In addition to these general classifications, additional subdivisions are very commonly deployed in opera and other classical music for solo voice. There are a number of such detailed classification schemes, some of which are historical or country-specific. See voice type.

## Induced vocal range
Where the above are largely achieved through practice and natural aptitude, adult vocal ranges can be obtained by means of physiological modification. The most notable example of this would be castrato singers, although modern examples include the lowering of the voice through Tobacco smoking.

# Vocal range in terms of frequency
In terms of frequency, human voices are roughly in the range of 80 Hz to 1100 Hz (that is, E2 to C6) for normal male and female voices together. The world records for high and low pitch extend well outside of this range, and can extend outside the range of human hearing.

# World records and extremes of vocal range
As noted above, claims of exceptionally wide vocal ranges are not uncommon among some singers. The biggest claim came from Charles Kellogg, who claimed to have a vocal range of 12.5 octaves. Kellogg could accurately imitate birdcalls, which sometimes went up into the ultrasonic range, according to Kellogg as high as 14,000 Hz (14 080Hz is A9). Some recordings of Kellogg's birdcalls still exist. However, Kellogg's claims are very hard to verify. 
In 2006 the Guinness Book of Records published several categories relating to extremes of "Human vocal range." It stated the following:
Females
- Greatest range: Eight octaves G2-G10, Georgia Brown, Brazil Watch Here (example of E7)
- Highest vocal note: G10 (25087Hz), Georgia Brown, Brazil
- Guinness lists the highest demanded note in the classical repertoire as G6 in 'Popoli di Tessaglia,' a concert aria by W. A. Mozart. However, this is not a standard repertory piece. The highest note in the standard repertoire is F6 in Mozart's aria "Der Holle Rache kocht in meinem Herzen" Watch Clip" (sometimes called "The Queen of the Night's aria," though this character actually has two arias) from the opera Die Zauberflote. It calls for four F6's, which is often cited as the highest note in classical vocal music (she sings an additional F6 during the first Act aria, "O Zittre nicht"). Several little-known works call for pitches higher than G6. For example, the soprano Mado Robin, who was known for her exceptionally high voice, sang a number of compositions created especially to exploit her highest notes, reaching C7 according to the Concise Oxford Dictionary of Opera (edited by Harold Rosenthal)
Males
- Greatest range: Six octaves, Tim Storms, USA Watch Clip
- Highest vocal note: CTemplate:Music8 Adam Lopez, Australia Watch Clip
- Lowest vocal note: B-2 (minus 2, two octaves below the grand staff)(8 Hz), Tim Storms, USA
- Guinness lists the lowest demanded note in the classical repertoire as a "Low D" (two Ds below Middle C) in Osmin's aria in Mozart's Die Entfuhrung aus dem Serail. Although Osmin's note is the lowest demanded and commonly performed in the operatic repertoire, Mahler's second symphony contains an optional BTemplate:Music1 in the choral section at the end of the piece: basses who cannot reach it are requested to remain silent rather than sing a BTemplate:Music2. Leonard Bernstein's Candide has an optional low B (a minor third below the low D) in a bass aria of its opera house version. Some choral works and songs also call for notes lower than the low D. For example, Pavel Chesnokov's "Do not deny me in my old age" features a basso profundo soloist, sometimes reaching as low as G1, depending on the arrangement.