The Hornbostel-Sachs

Hornbostel-Sachs

Hornbostel–Sachs is a system of musical instrument classification devised by Erich Moritz von Hornbostel and Curt Sachs, and first published in the Zeitschrift für Ethnologie in 1914. An English translation was published in the Galpin Society Journal in 1961...

 system of musical instrument classification

Musical instrument classification

At various times, and in various cultures, various schemes of musical instrument classification have been used.The most commonly used system in use in the west today divides instruments into string instruments, wind instruments and percussion instruments...

 defines chordophones as all instruments in which sound is primarily produced by the vibration of a string or strings that are stretched between fixed points. This group includes all instruments generally called string instrument

String instrument

A string instrument is a musical instrument that produces sound by means of vibrating strings. In the Hornbostel-Sachs scheme of musical instrument classification, used in organology, they are called chordophones...

s in the west, as well as many (but not all) keyboard instrument

Keyboard instrument

A keyboard instrument is a musical instrument which is played using a musical keyboard. The most common of these is the piano. Other widely used keyboard instruments include organs of various types as well as other mechanical, electromechanical and electronic instruments...

s, such as piano

Piano

The piano is a musical instrument played by means of a keyboard. It is one of the most popular instruments in the world. Widely used in classical and jazz music for solo performances, ensemble use, chamber music and accompaniment, the piano is also very popular as an aid to composing and rehearsal...

s and harpsichord

Harpsichord

A harpsichord is a musical instrument played by means of a keyboard. It produces sound by plucking a string when a key is pressed.In the narrow sense, "harpsichord" designates only the large wing-shaped instruments in which the strings are perpendicular to the keyboard...

s.

Simple chordophones or zithers

Zither

The zither is a musical string instrument, most commonly found in Slovenia, Austria, Hungary citera, northwestern Croatia, the southern regions of Germany, alpine Europe and East Asian cultures, including China...

 (31)

Instruments which are in essence simply a string or strings and a string bearer. These instruments may have a resonator box, but removing it should not render the instrument unplayable (although it may result in quite a different sound being produced). They include the piano

Piano

The piano is a musical instrument played by means of a keyboard. It is one of the most popular instruments in the world. Widely used in classical and jazz music for solo performances, ensemble use, chamber music and accompaniment, the piano is also very popular as an aid to composing and rehearsal...

 therefore, as well as other kinds of zither

Zither

The zither is a musical string instrument, most commonly found in Slovenia, Austria, Hungary citera, northwestern Croatia, the southern regions of Germany, alpine Europe and East Asian cultures, including China...

s such as the koto

Koto (musical instrument)

The koto is a traditional Japanese stringed musical instrument, similar to the Chinese guzheng, the Mongolian yatga, the Korean gayageum and the Vietnamese đàn tranh. The koto is the national instrument of Japan. Koto are about length, and made from kiri wood...

, and musical bow

Musical bow

The musical bow is a simple string musical instrument most archaic cultures as well as in many in the present day. It consisting of a string supported by a flexible stick 1.5 to 10 feet long, and strung end to end with a taut cord. Usually made out of wood...

s.

Bar or stick zithers (311)

The string bearer is bar shaped.

311.1 Musical bows - The string bearer is flexible (and curved).

311.11 Idiochord musical bows - The string is cut from the bark of the cane, remaining attached at each end.

311.111 Mono-idiochord musical bows - Containing one string only

311.112 Poly-idiochord musical bows or harp-bows - Containing several strings that pass over some type of bridge.

311.12 Heterochord musical bows - The string is of separate material from the bearer.

311.121 Mono-heterochord musical bows - The bow has one heterochord string only.

311.121.1 Without resonator.

311.121.11 Without tuning noose.

311.121.12 With tuning noose.

311.121.2 With resonator.

311.121.21 With independent resonator.

311.121.22 With resonator attached.

311.121.221 Without tuning noose.

311.121.222 With tuning noose.

311.122 Poly-heterochord musical bows - The bow has several heterochord strings.

311.122.1 Without tuning noose.

311.122.2 With tuning noose.

311.2 Stick zithers - With rigid string carrier

311.21 Musical bow/stick - The string carrier has one rigid and one flexible end.

311.22 True stick zithers - NB Round sticks which happen to be hollow by chance do not belong on this account to the tube zithers, but are round-bar zithers; however, instruments in which a tubular cavity is employed as a true resonator, like the modern Mexican harpa, are tube zithers.

311.221 With one resonator gourd.

311.222 With several resonator gourds.

Tube zithers (312)

The string bearer is a vaulted surface.

312.1 Whole tube zithers - The string carrier is a complete tube

312.11 Idiochord tube zithers.

312.12 Heterochord tube zithers.

312.121 Without extra resonator.

312.122 With extra resonator.

312.2 Half-tube zithers - The strings are stretched along the convex surface of a gutter.

312.21 Idiochord half-tube zithers.

312.22 Heterochord half-tube zithers.

Raft zithers (313)

The string bearer is composed of canes tied together in the manner of a raft

313.1 Idiochord raft zithers.

313.2 Heterochord raft zithers.

Board zithers (314)

The string bearer is a board

314.1 True board zithers.

314.11 Without resonator.

314.12 With resonator.

314.121 With resonator bowl.

314.122 With resonator box - the piano

Piano

The piano is a musical instrument played by means of a keyboard. It is one of the most popular instruments in the world. Widely used in classical and jazz music for solo performances, ensemble use, chamber music and accompaniment, the piano is also very popular as an aid to composing and rehearsal...

 is part of this subdivision.

314.2 Board zither variations.

314.21 Ground zithers.

314.22 Harp zithers.

Trough zithers (315)

The strings are stretched across the mouth of a trough

315.1 Without resonator.

315.2 With resonator.

Frame zithers (316)

The strings are stretched across an open frame

316.1 Without resonator.

316.2 With resonator.

Composite chordophones (32)

Acoustic and electro-acoustic instruments which have a resonator as an integral part of the instrument, and solid-body electric chordophones. This includes most western string instruments, including lutes such as violin

Violin

The violin is a string instrument, usually with four strings tuned in perfect fifths. It is the smallest, highest-pitched member of the violin family of string instruments, which includes the viola and cello....

s and guitar

Guitar

The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with...

s, and harp

Harp

The harp is a multi-stringed instrument which has the plane of its strings positioned perpendicularly to the soundboard. Organologically, it is in the general category of chordophones and has its own sub category . All harps have a neck, resonator and strings...

s.

Lutes (321)

The plane of the strings runs parallel with the resonator's surface.

321.1 Bow lutes - Each string has its own flexible carrier.

321.2 Yoke lutes or lyres - The strings are attached to a yoke which lies in the same plane as the sound-table and consists of two arms and a cross-bar.

321.21 Bowl lyres.

321.22 Box lyres.

321.3 Handle lutes - The string bearer is a plain handle.

321.31 Spike lutes.

321.311 Spike bow lutes.

321.312 Spike box lutes.

321.313 Spike tube lutes.

321.32 Necked lutes

321.321 Necked bowl lutes

• Angélique (instrument)
  Angélique (instrument)
  The angélique is a plucked string instrument of the lute family of the baroque era. It combines features of the lute, the harp, and the theorbo....
  
  
• Archlute
  Archlute
  The archlute is a European plucked string instrument developed around 1600 as a compromise between the very large theorbo, the size and re-entrant tuning of which made for difficulties in the performance of solo music, and the Renaissance tenor lute, which lacked the bass range of the theorbo...
  
  
• Balalaika
  Balalaika
  The balalaika is a stringed musical instrument popular in Russia, with a characteristic triangular body and three strings.The balalaika family of instruments includes instruments of various sizes, from the highest-pitched to the lowest, the prima balalaika, secunda balalaika, alto balalaika, bass...
  
  
• Barbat (lute)
  Barbat (lute)
  The barbat or barbud is a lute of ancient Persian origin. The Arabic Oud is derived from an ancient Persian barbat. Today's barbat, however, is essentially the same thing as today's oud: the instrument is often called the barbat when played in a Persian tradition, while called the oud when played...
  
  
• Bağlama
  Baglama
  thumb|180px|Cura and bağlamaThe bağlama is a stringed musical instrument shared by various cultures in the Eastern Mediterranean, Near East, and Central Asia....
  
  
• Biwa
  Biwa
  The is a Japanese short-necked fretted lute, often used in narrative storytelling. The biwa is the chosen instrument of Benten, goddess of music, eloquence, poetry, and education in Japanese Shinto....
  
  
• Bouzouki
  Bouzouki
  The bouzouki , is a musical instrument with Greek origin in the lute family. A mainstay of modern Greek music, the front of the body is flat and is usually heavily inlaid with mother-of-pearl. The instrument is played with a plectrum and has a sharp metallic sound, reminiscent of a mandolin but...
  
  
• Charango
  Charango
  The charango is a small Andean stringed instrument of the lute family, 66 cm long, traditionally made with the shell of the back of an armadillo. Primarily played in traditional Andean music, and is sometimes used by other Latin American musicians. Many contemporary charangos are now made with...
  
  
• Chitarra Italiana
  Chitarra Italiana
  Chitarra Italiana is a lute-shaped plucked instrument with 4 or 5 single strings, in a tuning similar to that of guitar. It was common in Italy during the Renaissance Era....
  
  
• Daguangxian
  Daguangxian
  The daguangxian is a Chinese bowed two-stringed musical instrument in the huqin family of instruments, held on the lap and played upright. It is used primarily in Taiwan and Fujian, among the Hakka and Min Nan peoples....
  
  
• Đàn tỳ bà
• Dombra
  Dombra
  The dombura is a long-necked lute popular in Central Asian nations...
  
  
• Domra
  Domra
  The domra is a long-necked Russian string instrument of the lute family with a round body and three or four metal strings.-History:In 1896, a student of Vasily Vasilievich Andreyev found a broken instrument in a stable in rural Russia...
  
  
• Dutar
  Dutar
  The dutar is a traditional long-necked two-stringed lute found in Iran, Central Asia and South Asia...
  
  
• Electric pipa
• Erhu
  Erhu
  The erhu is a two-stringed bowed musical instrument, more specifically a spike fiddle, which may also be called a "southern fiddle", and sometimes known in the Western world as the "Chinese violin" or a "Chinese two-stringed fiddle". It is used as a solo instrument as well as in small ensembles...
  
  
• Irish bouzouki
  Irish bouzouki
  The Irish bouzouki is a development of the octave mandolin adapted for Irish traditional and other folk music from the late 1960s onward.-Adoption for Celtic music:...
  
  
• Liuqin
  Liuqin
  The liuqin is a four-stringed Chinese mandolin with a pear-shaped body. It is small in size, almost a miniature copy of another Chinese plucked musical instrument, the pipa. The range of its voice is much higher than the pipa, and it has its own special place in Chinese music, whether in...
  
  
• Lute
  Lute
  Lute can refer generally to any plucked string instrument with a neck and a deep round back, or more specifically to an instrument from the family of European lutes....
  
  
• Mandocello
  Mandocello
  The mandocello is a plucked string instrument of the mandolin family. It has eight strings in four paired courses, tuned in 5ths like a mandolin, but is larger, and tuned CC-GG-dd-aa . It is to the mandolin what the cello is to the violin.-Construction:Mandocello construction is similar to the...
  
  
• Mandola
  Mandola
  The mandola or tenor mandola is a fretted, stringed musical instrument. It is to the mandolin what the viola is to the violin: the four double courses of strings tuned in fifths to the same pitches as the viola , a fifth lower than a mandolin...
  
  
• Mandolin
  Mandolin
  A mandolin is a musical instrument in the lute family . It descends from the mandore, a soprano member of the lute family. The mandolin soundboard comes in many shapes—but generally round or teardrop-shaped, sometimes with scrolls or other projections. A mandolin may have f-holes, or a single...
  
  
• Mandolute
  Mandolute
  A Mandolute is a North African instrument derived from the more traditional Oud. It is a ten string fretted instrument, sometimes called a mandoluth or mandol. It is slightly bigger than the mandola...
  
  
• Oud
  Oud
  The oud is a pear-shaped stringed instrument commonly used in North African and Middle Eastern music. The modern oud and the European lute both descend from a common ancestor via diverging paths...
  
  
• Pandura
  Pandura
  The pandura is an ancient Greek string instrument from the Mediterranean basin.It is derived from pandur, a Sumerian term for long-necked lutes...
  
  
• Pipa
  Pipa
  The pipa is a four-stringed Chinese musical instrument, belonging to the plucked category of instruments . Sometimes called the Chinese lute, the instrument has a pear-shaped wooden body with a varying number of frets ranging from 12–26...
  
  
• Qanbus
  Qanbus
  A qanbūs or gambus Yemeni migration saw the instrument spread to different parts of the Indian Ocean. In Muslim Southeast Asia , called the gambus, it sparked a whole musical genre of its own. Today it is played in Johor, South Malaysia, in the traditional dance Zapin...
  
  
• Rubab
• Setar
  Setar
  SETAR N.V., is the privatised full telecommunications service provider for the island of Aruba. The services provided by SETAR include: telephone, internet and GSM-related wireless services. SETAR also owns Tele Aruba....
  
  
• Sitar
  Sitar
  The 'Tablaman' is a plucked stringed instrument predominantly used in Hindustani classical music, where it has been ubiquitous since the Middle Ages...
  
  
• Surbahar
  Surbahar
  Surbahar , sometimes known as bass sitar, is a plucked string instrument used in the Hindustani classical music of North India. It is closely related to sitar, but it has a lower tone. Depending on the instrument's size, it is usually pitched two to five whole steps below the standard sitar, but...
  
  
• Tambura
  Tambura
  The tambura, tanpura, or tambora is a long-necked plucked lute . The body shape of the tambura somewhat resembles that of the sitar, but it has no frets – only the open strings are played to accompany other musicians...
  
  
• Tanbur
  Tanbur
  The term tanbūr can refer to various long-necked, fretted lutes originating in the Middle East or Central Asia. According to the New Grove Dictionary of Music and Musicians, "terminology presents a complicated situation. Nowadays the term tanbur is applied to a variety of distinct and related...
  
  
• Tanbur (Turkish)
  Tanbur (Turkish)
  The Tambur is a fretted string instrument of Turkey and the former lands of the Ottoman Empire. Like the ney, the armudi kemençe and the kudüm, it constitutes one of the four instruments of the basic quartet of Turkish classical music aka Sanat Musiği...
  
  
• Tembûr
  Tembûr
  The tembûr, a fretted string instrument, is a form of tanbūr. It is associated with the Ahl-e Haqq religion in Kurdish areas and in the Lorestān and Sistan va Baluchestan provinces of Iran. It is currently the only musical instrument used in Ahl-e Haqq rituals, and practitioners venerate the...
  
  
• Theorbo
  Theorbo
  A theorbo is a plucked string instrument. As a name, theorbo signifies a number of long-necked lutes with second pegboxes, such as the liuto attiorbato, the French théorbe des pièces, the English theorbo, the archlute, the German baroque lute, the angélique or angelica. The etymology of the name...
  
  
• Tiorbino
  Tiorbino
  A tiorbino, a little theorbo , is a rare stringed instrument, a type of long-necked lute resembling a theorbo but significantly smaller and pitched an octave higher...
  
  
• Tiqin
  Tiqin
  The tiqin is a name applied to several two-stringed Chinese bowed string musical instruments in the huqin family of instruments.-Types:There are several types of tiqin:*The tiqin used for kunqu opera...
  
  
• Topshur
  Topshur
  Topshur is a two-stringed plucked or strummed lute played by the Altayans. Related instruments include the Kazakh dombra, the Mongolian tovshuur and the Tuvan doshpuluur. The topshur's strings are tuned to an interval of a fourth...
  
  
• Veena
  Veena
  Veena may refer to one of several Indian plucked instruments:With frets*Rudra veena, plucked string instrument used in Hindustani music*Saraswati veena, plucked string instrument used in Carnatic musicFretless...
  
  
• Zhonghu
  Zhonghu
  The zhonghu is a low-pitched Chinese bowed string instrument. Together with the erhu and gaohu, it is a member of the huqin family, and was developed in the 20th century as the alto member of the huqin family .The zhonghu is analogous with the erhu, but is slightly larger and...
  
  

321.322 Necked box lutes -

• Banjo
  Banjo
  In the 1830s Sweeney became the first white man to play the banjo on stage. His version of the instrument replaced the gourd with a drum-like sound box and included four full-length strings alongside a short fifth-string. There is no proof, however, that Sweeney invented either innovation. This new...
  
  
• Guitar
  Guitar
  The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with...
  
  
  • Acoustic guitar
    Acoustic guitar
    An acoustic guitar is a guitar that uses only an acoustic sound board. The air in this cavity resonates with the vibrational modes of the string and at low frequencies, which depend on the size of the box, the chamber acts like a Helmholtz resonator, increasing or decreasing the volume of the sound...
    
    
    • Acoustic bass guitar
      Acoustic bass guitar
      The acoustic bass guitar is a bass instrument with a hollow wooden body similar to, though usually somewhat larger than a steel-string acoustic guitar...
      
      
    • Baroque guitar
      Baroque guitar
      The Baroque guitar is a guitar from the baroque era , an ancestor of the modern classical guitar. The term is also used for modern instruments made in the same style....
      
      
    • Classical guitar
      Classical guitar
      The classical guitar is a 6-stringed plucked string instrument from the family of instruments called chordophones...
      
      
      • Extended-range classical guitar
      • Tenor guitar
        Tenor guitar
        1932 Martin 0-18 T Sunburst Tenor Guitar|thumb|rightThe tenor guitar or four-string guitar is a slightly smaller, four-string relative of the steel-string acoustic guitar or electric guitar. The instrument was developed so that players of the four-string tenor banjo could double on the guitar...
        
        
    • Flamenco guitar
      Flamenco guitar
      A flamenco guitar is a guitar similar to a classical guitar. Flamenco guitar also refers to toque, the guitar-playing part of the art of Flamenco.-Brief history:...
      
      
    • Guitarrón mexicano
    • Harp guitar
      Harp guitar
      ]The harp guitar is a stringed instrument with a history of well over two centuries. While there are several unrelated historical stringed instruments that have appropriated the name “harp-guitar” over the centuries, the term today is understood as the accepted vernacular to refer to a particular...
      
      
    • Steel-string acoustic guitar
      Steel-string acoustic guitar
      A steel-string acoustic guitar is a modern form of guitar descended from the classical guitar, but strung with steel strings for a brighter, louder sound...
      
      
      • Archtop guitar
        Archtop guitar
        An archtop guitar is a steel-stringed acoustic or semi-acoustic guitar with a full body and a distinctive arched top, whose sound is particularly popular with blues and jazz players.Typically, an archtop guitar has:* 6 strings...
        
        
      • Guitar battente
      • Resonator guitar
        Resonator guitar
        A resonator guitar or resophonic guitar is an acoustic guitar whose sound is produced by one or more spun metal cones instead of the wooden sound board . Resonator guitars were originally designed to be louder than conventional acoustic guitars which were overwhelmed by horns and percussion...
        
        
        • Cümbüş
          Cümbüs
          The cümbüş is a Turkish stringed instrument of relatively modern origin. Developed in the early 20th century by Zeynelabidin Cümbüş as an oud-like instrument that could be heard as part of a larger ensemble. In construction it resembles both the American banjo and the Middle Eastern oud. A...
          
          
        • Dobro
          Dobro
          Dobro is a registered trademark, now owned by Gibson Guitar Corporation and used for a particular design of resonator guitar.The name has a long and involved history, interwoven with that of the resonator guitar...
          
          
      • Ten-string guitar
        Ten-string guitar
        There are many varieties of ten-string guitar, including:* Both electric and acoustic guitars.* Instruments used principally for classical, folk and popular music.* Both coursed and uncoursed instruments.-Ten-stringed harp guitars:...
        
        
      • Twelve-string guitar
        • Bajo sexto
          Bajo sexto
          A bajo sexto is a musical instrument with 12 strings in 6 double courses, used in Mexican music. It is used primarily in norteño music of northern Mexico and across the border in the music of south Texas known as "Tex-Mex", "conjunto, or "música mexicana-tejana".A similar instrument with five...
          
          
        • Portuguese guitar
          Portuguese guitar
          The Portuguese guitar or Portuguese guitarra is a plucked string instrument with twelve steel strings, strung in six courses comprising two strings each. It is one of the few musical instruments to use Preston tuners. It is most notably associated with fado.-History:The origin of the Portuguese...
          
          
    • Russian guitar
      Russian guitar
      The Russian guitar is a seven-string acoustic guitar that arrived in Russia toward the end of the 18th century and the beginning of the 19th century, most probably as an evolution of the cittern, kobza, and torban...
      
      
  • Electric guitar
    Electric guitar
    An electric guitar is a guitar that uses the principle of direct electromagnetic induction to convert vibrations of its metal strings into electric audio signals. The signal generated by an electric guitar is too weak to drive a loudspeaker, so it is amplified before sending it to a loudspeaker...
    
    
    • Chambered
    • Eight-string guitar
    • Electric-acoustic guitar
    • Semi-acoustic guitar
      Semi-acoustic guitar
      A semi-acoustic guitar or hollow-body electric is a type of electric guitar with both a sound box and one or more electric pickups. This is not the same as an electric acoustic guitar, which is an acoustic guitar with the addition of pickups or other means of amplification, either added by the...
      
      
    • Solid body
    • String-through body
  • Ukulele
    Ukulele
    The ukulele, ; from ; it is a subset of the guitar family of instruments, generally with four nylon or gut strings or four courses of strings....
    
    
• Violin family
  Violin family
  The violin family of musical instruments was developed in Italy in the sixteenth century. The standard modern violin family consists of the violin, viola, cello, and double bass....
  
  
  • Double Bass
    Double bass
    The double bass, also called the string bass, upright bass, standup bass or contrabass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra, with strings usually tuned to E1, A1, D2 and G2...
    
    
  • Cello
    Cello
    The cello is a bowed string instrument with four strings tuned in perfect fifths. It is a member of the violin family of musical instruments, which also includes the violin, viola, and double bass. Old forms of the instrument in the Baroque era are baryton and viol .A person who plays a cello is...
    
    
  • Octobass
    Octobass
    The octobass is an extremely large bowed string instrument constructed about 1850 in Paris by the French luthier Jean Baptiste Vuillaume...
    
    
  • Viola
    Viola
    The viola is a bowed string instrument. It is the middle voice of the violin family, between the violin and the cello.- Form :The viola is similar in material and construction to the violin. A full-size viola's body is between and longer than the body of a full-size violin , with an average...
    
    
  • Violin
    Violin
    The violin is a string instrument, usually with four strings tuned in perfect fifths. It is the smallest, highest-pitched member of the violin family of string instruments, which includes the viola and cello....
    
    

Harps (322)

The plane of the strings lies perpendicular to the resonator's surface.

322.1 Open harps - The harp has no pillar.

322.11 Arched harps.

322.12 Angular harps.

322.2 Frame harps - The harp has a pillar

322.21 Without tuning mechanism.

322.211 Diatonic frame harps.

322.212 Chromatic frame harps.

322.212.1 With all strings in one plane.

322.212.2 With strings in two planes crossing each other.

322.22 With tuning action.

322.221 With manual tuning action.

322.222 With pedal action.

Harp lutes (323)

The plane of the strings lies at right angles to the sound-table; a line joining the lower ends of the strings would be perpendicular to the neck. Notched bridge

• African Harp guitar

Unclassified chordophones (33)

These instruments may be classified with a suffix, based on how the strings are caused to vibrate.

• 4: Hammers or beaters
• 5: Bare hands and fingers
• 6: Plectrum
  Plectrum
  A plectrum is a small flat tool used to pluck or strum a stringed instrument. For hand-held instruments such as guitars and mandolins, the plectrum is often called a pick, and is a separate tool held in the player's hand...
  
  
• 7: Bowing
  • 71: Using a bow
    Bow (music)
    In music, a bow is moved across some part of a musical instrument, causing vibration which the instrument emits as sound. The vast majority of bows are used with string instruments, although some bows are used with musical saws and other bowed idiophones....
    
    
  • 72: Using a wheel
  • 73: Using a ribbon
• 8: Keyboard
  Musical keyboard
  A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument, particularly the piano. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the...
  
  
• 9: Using a mechanical drive