Most singing involves shaping the voice to form words, but types of voice instrumental music which use open sounds or nonsense syllables ("vocables") also exist, for instance, scat singing and yodeling. Solfege assigns certain syllables to notes in the scale.
Nearly anyone who can speak can sing, since in many respects singing is merely sustained speech. It can be informal and just for pleasure, for example, singing in the shower; or it can be very formal, such as singing done professionally as a performance or in a recording studio. Singing at a high amateur or professional level usually requires a great deal of regular practice, and/or instruction. Many top-quality singers regularly take or have taken a great deal of professional instruction from one or more voice coaches.
Singing is often done in a group, such as a choir, and may be accompanied by musical instruments, a full orchestra, or a band. Singing with no instrumental accompaniment is called a cappella.
Show choir is a combination of singing and dancing. Many schools and colleges offer show choir groups for students to participate in. Not only must participants be able to sing well and blend in with a group, but they must be able to dance at the same time. This requires endurance, flexibility, and strong vocals, which can all be acquired through practice.
It is also imperitive that singers continuously practise with drills, [[1]voice exercises] and strengthening activities. Without constant practice, the singers range can be significantly decreased, requiring extra rehearsal to regain the voices' previous capability.
In hardcore punk, hoarse shouting takes the place of singing, while in emo, some bands scream rather than sing. In metal, particularly the sub-genre of death metal, low growls called death grunts are favoured over standard singing.
Techniques
The human voice is usually considered to have at least three voice registers; ranging from lowest to highest, they are the chest register, head register, and falsetto. (The whistle register, comprising the highest notes that a human voice can reach, is also often considered a "full" register, though the ability to use it well is fairly rare.) Some singers remain in a single range (usually the chest register) throughout their songs, but many will switch between these different ranges in order to produce a wide range of pitches, or even simply for effect. Yodelling is a technique that requires rapidly switching between at least two different registers many times in the same phrase, producing a distinct high-low-high-low sound.
Vibrato is a technique used by singers (and many instrumentalists, for instance, string instruments that are played with a bow can produce vibrato tones) in which a sustained note actually wavers very quickly and consistently between a very slightly higher and a lower tone, giving the note a slight quaver.
Melisma occurs when a singer switches pitch while singing the same syllable. It is used heavily in operatic singing, as well as to a somewhat lesser extent in popular music.