Most hurdy gurdies have multiple "drone strings" which provide a constant pitch accompaniment to the melody, resulting in a sound similar to that of bagpipes. For this reason, the hurdy gurdy is often used interchangeably with or along with bagpipes, particularly in French and contemporary Hungarian folk music. Many folk music festivals in Europe feature music groups with hurdy gurdy players, but the most famous annual festival is at Saint-Chartier, in the Indre département, in central France, during the week nearest July 14 (Bastille Day).
The hurdy gurdy is thought to have originated in either Western Europe or the Middle East some time prior to the eleventh century A.D. One of the earliest forms of the hurdy gurdy was the organistrum, a large instrument with a guitar-shaped body and a long neck in which the keys were set (covering one diatonic octave). The organistrum had a single melody string and two drone strings which ran over a common bridge and a relatively small wheel. Due to its size, the organistrum was played by two people, one of whom turned the crank while the other pulled the keys upward. Pulling keys upward is a cumbersome playing technique, and as a result only slow tunes could be played on the organistrum. The pitches on the organistrum were set according to Pythagorean temperament and the instrument was primarily used in monastic and church settings to accompany choral music. The abbot Odo of Cluny (died 942) is supposed to have written a short description of the construction of the organistrum entitled Quomodo organistrum construatur (How the Organistrum Is Made), known through a much-later copy, but its authenticity is very doubtful. Another 10th century treatise thought to have mentioned an instrument similar to the hurdy gurdy is an Arabic musical compendium written by Al Zirikli. One of the earliest visual depictions of the organistrum is from the twelfth-century ´Pórtico de la Gloria (Portal of Glory) on the cathedral at Santiago de Compostela, Galicia, Spain, which includes a carving of two musicians playing an organistrum.
Later on the organistrum was reduced in size to allow a single player to both turn the crank and manipulate the keys. The solo organistrum was known from Spain and France, but was largely replaced by the symphonia, a small box-shaped version of the hurdy gurdy with three strings and a diatonic keyboard. At about the same time as the symphonia was developed, a new form of key pressed from beneath were developed. These keys were much more practical in faster music and easier to handle and eventually completely replaced keys pulled up from above. Medieval depictions of the symphonia show both types of keys.
During the Renaissance, the hurdy gurdy was a very popular instrument, along with the bagpipe, and a characteristic form with a short neck and a boxy body with a curved tail end developed. It was about this time that buzzing bridges first appear in depictions of the instrument. The buzzing bridge (commonly called the dog) is an asymmetrical bridge that rests under a drone string on the sound board. When the wheel is accelerated, one foot of the bridge lifts up from the soundboard and vibrates, creating a buzzing sound. The buzzing bridge is thought to have been borrowed from the tromba marina(monochord), a bowed string instrument.
During the late Renaissance, two characteristic shapes of hurdy gurdies developed. The first was guitar-shaped and the second had a rounded lute-type body made of staves. The lute body is especially characteristic of French instruments.
By the end of the 17th century changing musical tastes that demanded greater polyphonic capabilities than the hurdy gurdy could offer had pushed the instrument to the lowest social classes; as a result it acquired names like the German Bauernleier ‘peasant’s lyre’ and Bettlerleier ‘beggar’s lyre.’ During the 18th century, however, French Rococo tastes for rustic diversions brought the hurdy gurdy back to the attention of the upper classes, where it acquired tremendous popularity among the nobility, with famous composers writing works for the hurdy gurdy (the most famous of which is Nicolas Chédeville’s Il pastor Fido, attributed to Vivaldi). At this time the most common style of hurdy gurdy developed, the six-string vielle à roue. This instrument has two melody strings and four drones tuned such that by turning drones on or off, the instrument can be played in multiple keys (e.g., C and G or G and D).
During this time the hurdy gurdy also spread further east, where further variations developed in western Slavic countries, German-speaking areas and Hungary (see the list of types below for more information on these). Most types of hurdy gurdy were essentially extinct by the early twentieth century, but a few sorts have survived to the present day, the best-known of which are the French vielle à roue, the Hungarian tekerőlant, and the Spanish zanfona. In Ukraine, a variety called the lira was widely used by blind street musicians, most of whom were purged by Stalin in the 1930s. Revivals have been underway for many years in Sweden, Germany, Austria, Czech Republic, Poland, Russia, Italy, and Portugal. The revival of hurdy gurdies has resulted in the instrument’s use in a variety of styles of music (see the list of recordings that use hurdy gurdy), including contemporary forms not typically associated with the hurdy gurdy.
The hurdy-gurdy appears to tbe the instrument played by Der Leiermann, the melancholy last song of Schubert's Winterreise 
The hurdy gurdy is featured and played prominantly in the film Captains Courageous (1937) as the instrument belonging to the character Manuel, acted by Spencer Tracy.
This confusion over what the name hurdy gurdy means is particular to English, although similar confusion over other terms for the instrument occurs in German and Hungarian due to unfamiliarity with the hurdy gurdy. The French call the barrel organ the Orgue de Barbarie ("Barbary organ"), and the Germans Drehorgel ("turned organ"), instead of Drehleier ("turning lyre").
Due to the prominence of the French tradition, many instrument and performance terms used in English are commonly taken from the French, and players generally need to know these terms to read relevant literature. Such common terms include the following:
According to the Oxford English Dictionary, the origin of the term hurdy gurdy is onomatopoetic in origin, after the repetitive warble in pitch that characterizes instruments with solid wooden wheels that have warped due to changes in humidity or after the sound of the buzzing-bridge.
Some have suggested other origins for the term, including the following folk etymology:
hurdy = a person's backside + gurdy = a reel with a crank, used to reel in fishing nets on a boat. This pejorative name was applied to the French instrument in England, during the eighteenth century.(There are a number of problems with this putative etymology. Among them are (1) hurdy is not known as an English term, and (2) the term for the crank (hurdy gurdy, not gurdy) was first recorded in 1883, based on the term for the instrument.)
An alternative folk etymology suggests that the term comes from an anglicized form of the French harpe de gourde.
The instrument is sometimes more descriptively called a wheel fiddle in English, but this term is not in general use among players of the instrument. The Hungarian name tekerőlant and the alternate forgólant both mean "turning lute." An alternate German name, Bauernleier, means "peasant's lyre". (Leier, lant, and related terms today are generally used to refer to members of the lute or lyre family, but historically had a broader range of meaning and were used for many types of stringed instruments.)
Another Hungarian name for the instrument is nyenyere, which is thought to be an onomatopoeic reference to the repetitive warble produced by a wheel that is not even. Note that this term was considered derogatory in the Hungarian lowlands, but was the normal term for the instrument on Csepel island directly south of Budapest.
There is no standardized design for the hurdy gurdy today, although the six-stringed French vielle a roue is the best known and most common sort. A number of regional forms developed, but outside of France the instrument was considered a folk instrument and there were no schools of construction that could have determined a standard form.
There are two primary body styles for contemporary instruments: guitar-bodied and lute-backed. Both forms are found in French-speaking areas, while guitar-bodied instruments are the general form elsewhere. The box form of the simphonia is also commonly found among players of early music and historical reenactors.
The drone strings produce steady sounds at fixed pitches. The melody string(s) (French chanterelle(s), Hungarian dallamhúr(ok)) are stopped with tangents attached to keys that change the vibration length of the string, much as a guitarist uses his or her fingers on the fretboard of a guitar. In the earliest hurdy gurdies these keys were arranged to provide a Pythagorean temperament, but in later instruments the tunings have varied widely, with equal temperament most common in order to allow for easier blending with other instruments. However, because the tangents can be adjusted to tune individual notes, it is possible to tune hurdy gurdies to almost any temperament as needed. Most contemporary hurdy gurdies have 24 keys that cover a range of two chromatic octaves.
In order to achieve proper intonation and sound quality, each string of a hurdy gurdy must be wrapped with cotton or similar fibers. The cotton on melody strings tends to be quite light, while drone strings have heavier cotton. Improper cottoning results in a raspy tone, especially at higher pitches. In addition, individual strings (in particular the melody strings) often have to have their height above the wheel surface adjusted by having small pieces of paper placed between the strings and the bridge, a process called shimming. Shimming and cottoning are connected processes since either one can affect the geometry of the instrument’s strings.
On French-style instruments, the sensitivity of the buzzing bridge can be altered by turning a peg called a tirant in the tailpiece of the instrument that is connected by a wire or thread to the trompette. The tirant adjusts the lateral pressure on the trompette and thereby sets the sensitivity of the buzzing bridge to changes in wheel velocity. There are various stylistic techniques that are used as the player turns the crank, speeding up the wheel at various points in its revolution. Each sped-up "hit" produces a distinct buzzing sound. These hits are under the control of the player, and are not automatic, having to be put in with each complete turn of the wheel.
On the Hungarian tekerő the same control is achieved by using a wedge called the recsegőék (control wedge (literally "buzzer wedge") that pushes the drone string downward. In traditional tekerő playing, the buzzing bridge is controlled entirely by the wrist of the player and has a very different sound and rhythmic possibilities from those available on French instruments.