There are two types of vibrato: ‘hammer’ and ‘laryngeal’ vibrato. Hammer vibrato is particularly characterised by pulsation, whereas laryngeal vibrato is characterised by both pulsation and difference in pitch. Both vibratos may be acquired through practice.
Hammer vibrato is also known as ‘vocal cord’ vibrato. It sounds like a long sequence of pulsations on the same note. It may be thought of as a long line of attacks. Hammer vibrato is most likely produced at the vocal cord level, i.e. Level 1 (see ’Various levels of the vocal tract’).
If hammer vibrato is used in Overdrive or Edge it may sound like a bleating sheep or a machine gun. The Vibrato may be trained to reach the desired speed of pulsations. It is often heard in ethnic musics such as Arab singing and flamenco singing. It is also used by some French singers like Edith Piaf and Charles Aznavour and by several folk singers.
Singers who use or used hammer vibrato
Antony Hegarty (Antony and the Johnsons), Beth Hart, Buffy Saint Marie, Cher, Eartha Kitt, John Denver, Randy Crawford, and Robin Gibb (Bee Gees)
The second type of vibrato is laryngeal vibrato or ‘throat’ vibrato. The difference between notes in this vibrato may be more or less distinct. Laryngeal vibrato is achieved by moving the larynx up and down creating a variation in pitch. This vibrato is most likely produced in a combination of levels from 1-4. The vocal cords produce the pitch and the hypopharynx produces the speed (see ’Various levels of the vocal tract’).
This vibrato is often slower and has a broader pitch range than hammer vibrato and also has a larger difference between notes. If r jaw and tongue are very loose, laryngeal vibrato may from time to time be accompanied by a quivering tongue, jaw and sometimes head. Distinct laryngeal vibrato is often used by crooners, jazz singers and blues singers. 288
It is possible to control the pitch and the speed of the vibrato.
Singers who use or used laryngeal vibrato
Birgit Nilsson, Bonnie Raitt, Carpenters, Elvis Presley, James Morris, Jessica Harper, Joni Mitchell, King Diamond, Liza Minelli, Nicolai Gedda, Ronnie James Dio, and Sebastian Bach (Skid Row)
Skilled singers use vibrato to emphasise expression. Both types of vibrato can be used in a song.
Many singers adjust the speed of the vibrato to the rhythmic subdivisions of the song. For example, many singers choose to put a slow vibrato in a slow song and a fast vibrato in a fast song. A frequently used method to emphasise intensity is to start on a note without a vibrato and then gradually add it towards the end.
The singer may add intensity at special places in the song by making the vibrato increasingly faster
or by slowing it down
Different musical styles have different individual preferences as regards the types of vibrato used. Classical singers often sing with a larger vibrato than rock singers. Rock singers hardly ever start a note with vibrato, whereas classical singers almost always use vibrato from the beginning of the note.
If vibrato is wanted in Overdrive, Edge and Curbing, it must be added consciously. Vibrato usually costs even more energy in these modes
Making the vibrato faster
Most singers have a tendency to add more vibrato as they get older, unless they are aware of the issue and take precautionary measures.