Guitar in the context of "Cittern"

The kithara (Greek: κιθάρα, romanized: kithára), Latinized as cithara, was an ancient Greek musical instrument in the yoke lutes family. It was a seven-stringed professional version of the lyre, which was regarded as a rustic, or folk instrument, appropriate for teaching music to beginners. As opposed to the simpler lyre, the cithara was primarily used by professional musicians, called kitharodes. In modern Greek, the word kithara has come to mean "guitar"; etymologically, the word guitar derives from kithara.

In musical instrument classification, string instruments, or chordophones, are musical instruments that produce sound from vibrating strings when a performer strums, plucks, strikes or sounds the strings in varying manners.

Musicians play some string instruments, like guitars, by plucking the strings with their fingers or a plectrum (pick), and others by hitting the strings with a light wooden hammer or by rubbing the strings with a bow, like violins. In some keyboard instruments, such as the harpsichord, the musician presses a key that plucks the string. Other musical instruments generate sound by striking the string.

Lutes are stringed musical instruments that include a body and "a neck which serves both as a handle and as a means of stretching the strings beyond the body".

The lute family includes not only short-necked plucked lutes such as the lute, oud, pipa, guitar, citole, gittern, mandore, rubab, and gambus and long-necked plucked lutes such as banjo, tanbura, bağlama, bouzouki, veena, theorbo, archlute, pandura, sitar, tanbur, setar, but also bowed instruments such as the yaylı tambur, rebab, erhu, and the entire family of viols and violins.

A soundboard (or sounding board) is the surface of a string instrument that the strings vibrate against, usually via some sort of bridge. Depending on the instrument, it is also called a top, top plate, resonator, table, sound-table, or belly. It is usually made of a softwood, often spruce.

Pianos, guitars, banjos, and many other stringed instruments incorporate soundboards. The resonant properties of the soundboard and the interior of the instrument greatly increase the loudness of the vibrating strings. "The sound board is probably the most important element of a guitar in terms of its influence on the quality of the instrument's tone [timbre]."

A chord chart (or chart) is a form of musical notation that describes the basic harmonic and rhythmic information for a song or tune. It is the most common form of notation used by professional session musicians playing jazz or popular music. It is intended primarily for a rhythm section (usually consisting of piano, guitar, drums and bass). In these genres the musicians are expected to be able to improvise the individual notes used for the chords (the "voicing") and the appropriate ornamentation, counter melody or bassline.

In some chord charts, the harmony is given as a series of chord symbols above a traditional musical staff. The rhythmic information can be very specific and written using a form of traditional notation, sometimes called rhythmic notation, or it can be completely unspecified using slash notation, allowing the musician to fill the bar with chords or fills any way they see fit (called comping). In Nashville notation the key is left unspecified on the chart by substituting numbers for chord names. This facilitates on-the-spot key changes to songs. Chord charts may also include explicit parts written in modern music notation (such as a musical riff that the song is dependent on for character), lyrics or lyric fragments, and various other information to help the musician compose and play their part.

An orchestra (/ˈɔːrkɪstrə/ ; OR-ki-strə) is a large instrumental ensemble typical of classical music, which combines instruments from different families. There are typically four main sections of instruments:

• The string section, including the violin, viola, cello, and double bass
• The woodwind section, including the flute, oboe, clarinet, bassoon, and occasionally saxophone
• The brass section, including the French horn (commonly known as the "horn"), trumpet, trombone, cornet, and tuba, and sometimes euphonium
• The percussion section, including the timpani, snare drum, bass drum, cymbals, triangle, tambourine, tam-tam and mallet percussion instruments

Other instruments such as the piano, harpsichord, pipe organ, and celesta may sometimes appear in a fifth keyboard section or may stand alone as soloist instruments, as may the concert harp and, for performances of some modern compositions, electronic instruments, and guitars.

Accompaniment is the musical part which provides the rhythmic and/or harmonic support for the melody or main themes of a song or instrumental piece. There are many different styles and types of accompaniment in different genres and styles of music. In homophonic music, the main accompaniment approach used in popular music, a clear vocal melody is supported by subordinate chords. In popular music and traditional music, the accompaniment parts typically provide the "beat" for the music and outline the chord progression of the song or instrumental piece.

The accompaniment for a vocal melody or instrumental solo can be played by a single musician playing an instrument such as piano, pipe organ, or guitar. While any instrument can in theory be used as an accompaniment instrument, keyboard and guitar-family instruments tend to be used if there is only a single instrument, as these instruments can play chords and basslines simultaneously (chords and a bassline are easier to play simultaneously on keyboard instruments, but a fingerpicking guitarist can play chords and a bassline simultaneously on guitar). A solo singer can accompany themself by playing guitar or piano while they sing, and in some rare cases, a solo singer can even accompany themself just using their voice and body (e.g., Bobby McFerrin).

The Museu de la Música de Barcelona (English: Music Museum of Barcelona) is a museum in Barcelona, Spain that houses a collection of musical instruments from around the world as well as biographical documents, from ancient civilisations to new technologies from the 21st century. The museum collection comprises 2000 musical instruments, 500 of which are on display, including one of the best guitar collections of the world. The museum covers historical, conservational and research aspects and promotes the city’s musical heritage.

The Museu de la Música is administered by the City Council. Since 2007 its headquarters are found on the second floor of the L'Auditori de Barcelona in the Fort Pienc neighbourhood.

Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum and alternating current. Oscillations can be used in physics to approximate complex interactions, such as those between atoms.

Oscillations occur not only in mechanical systems but also in dynamic systems in virtually every area of science: for example the beating of the human heart (for circulation), business cycles in economics, predator–prey population cycles in ecology, geothermal geysers in geology, vibration of strings in guitar and other string instruments, periodic firing of nerve cells in the brain, and the periodic swelling of Cepheid variable stars in astronomy. The term vibration is precisely used to describe a mechanical oscillation.