The Moodswinger is a twelve-string electric zither with an additional third bridge designed by Yuri Landman. The rod which functions as the third bridge divides the strings into two sections to cause an overtone multiphonic sound. One of the copies of the instrument is part of the collection of the Musical Instrument Museum in Phoenix, Arizona.
In March 2006 Landman was contacted by the noise band Liars to make an instrument for them. After 6 months he finished two copies of The Moodswinger, an electric 12-string 3rd-bridge overtone koto, one for guitarist/drummer Aaron Hemphill and one for himself.  Although it closely resembles an electric guitar, it is actually a zither, as it has neither frets nor a proper neck. The pickup and electronics are built into the neck instead of in the body like usual electric guitars. In 2008 the Moodswinger II was released as a serial product. Jessie Stein of The Luyas owns a copy.
In 2009 Landman created a derivative version of the instrument called the Home Swinger, for workshops at festivals, where participants built their own copy within four hours. In 2010 the Musical Instrument Museum in Phoenix included a Moodswinger as well as a Home Swinger in their collection as two of the pieces of the Dutch section of musical instrument inventions.
The 3rd bridge divides the strings into two segments with different pitches. Depending on where the string is played, a bell-like harmonic second tone is created. The string resonates more or less when the back side is struck, depending on the position of the 3rd bridge along the string. This can be explained by acoustic resonance and microtonality. At harmonic nodal positions, the string resonates more than at other positions. For instance, dividing the string 1/3 + 2/3 creates a clear overtone, while 24/33 + 9/33 creates an indistinct overtone. The color dotted scale indicates the simple-number ratios up to the 7 limit (on the Moodswinger II to the 8 limit.) On these positions just intoned harmonic dyads occur.
The Moodswinger is focused on a non-atonal playing technique. A mathematical scale is added to specify 23 harmonic positions on the strings. Because the instrument has 12 strings, tuned in a circle of fourths, it is always possible to play every note of the equal tempered scale. However some positions have a + or - indication, because the equal tempered scale is not a perfect well-tempered scale. 
The tuning of this instrument is a circle of fourths: E-A-D-G-C-F-A#-D#-G#-C#-F#-B, arranged in 3 clusters of 4 strings each to make the field of strings better readable.
Because of this tuning all five neighbouring strings form a harmonic pentatonic scale and all seven neighbouring strings form a major scale, available in every key. This allows a very easy fingerpicking technique without picking false notes, if the right key is chosen.
The instrument has 3 printed scales, used as guides for positioning the moveable third bridge and reading the played notes:
On the Moodswinger II the 1/8, 3/8, 5/8 and 7/8 are Blue dotted. On the Home Swinger the same color system occurs.
The sound of a 3rd-bridged string is a combination of 3 tones. A soft-sounding attack tone of the string part hit at the body side, the corresponding overtone of both sides and a resonating low fundamental tone of the counterpart of the string at the head side. The diagram below shows the tone combinations of the overtone (above) and the low tone of the counterpart (below). The attack tone is in most positions exact the same note as the overtone. Exceptions are 3/4, 3/5, 3/7 and 5/7. In the 3/... positions the overtone is a perfect fifth of the attack tone, in the 5/7 positions the overtone is a major third of the attack tone.
|Bridge position||Colour codes||Attack tone : open string ||Resonating fundamental of the counterpart:  open string||Corresponding overtone |
related : open string
|Corresponding overtone : fundamental of the counterpart||Cents |
of string parts 
Body : Neck
|1/16||Grey line||4 octaves||Just minor second (16:15)||4 octaves||Just major seventh (15:8) 22ma||111.73 : 4800.00|
|1/12||Green line||Just perfect fifth (3:2) 22ma||Lesser undecimal neutral second (12:11)||Just perfect fifth (3:2) 22ma||Lesser undecimal tritone (11:8) 22ma||150.64 : 4302.00|
|1/11||Yellow line||Lesser undecimal tritone (11:8) 22ma||Greater undecimal neutral second (11:10)||Lesser undecimal tritone (11:8) 22ma||Just major third (5:4) 22ma||165.00 : 4151.30|
|1/10||Orange line||Just major third (5:4) 22ma||Lesser just major second (10:9)||Just major third (5:4) 22ma||Greater just major second (9:8) 22ma||182.40 : 3986.30|
|1/9||Red line||Greater just major second (9:8) 22ma||Greater just major second (9:8)||Greater just major second (9:8) 22ma||3 octaves||203.91 : 3803.90|
|1/8||Grey line||3 octaves||Septimal major second (8:7)||3 octaves||Harmonic seventh (7:4) 15ma||231.17 : 3600.00|
|1/7||Blue dot||Harmonic seventh (7:4) 15ma||Septimal minor third (7:6)||Harmonic seventh (7:4) 15ma||Just perfect fifth (3:2) 15ma||266.87 : 3368.80|
|1/6||Green dot||Just perfect fifth (3:2) 15ma||Just minor third (6:5)||Just perfect fifth (3:2) 15ma||Just major third (5:4) 15ma||315.64 : 3102.00|
|1/5||Yellow dot||Just major third (5:4) 15ma||Just major third (5:4)||Just major third (5:4) 15ma||2 octaves||386.31 : 2786.30|
|1/4||Orange dot||2 octaves||Just perfect fourth (4:3)||2 octaves||Just perfect fifth (3:2) 8va||498.04 : 2400.00|
|2/7||Blue dot||Harmonic seventh (7:4) 8va||Lesser septimal tritone (7:5)||Harmonic seventh (7:4) 15ma||Just major third (5:4) 15ma||582.51 : 1782.51|
|1/3||Red dot||Just perfect fifth (3:2) 8va||Just perfect fifth (3:2)||Just perfect fifth (3:2) 15ma||Octave||701.96 : 1901.96|
|2/5||Yellow dot||Just major third (5:4) 8va||Just major sixth (5:3)||Just major third (5:4) 15ma||Just perfect fifth (3:2) 8va||884.36 : 1586.31|
|3/7||Blue dot||Septimal minor third (7:6) 8va||Harmonic seventh (7:4)||Harmonic seventh (7:4) 15ma||2 octaves||968.83 : 1466.87|
|1/2||Grey dot||Octave||Octave||Octave||Unison||1200.00 : 1200.00|
|4/7||Blue dot||Harmonic seventh (7:4)||Septimal minor third (7:6) 8va||Harmonic seventh (7:4) 15ma||Just perfect fifth (3:2) 8va||1466.87 : 968.83|
|3/5||Yellow dot||Just major sixth (5:3)||Just major third (5:4) 8va||Just major third (5:4) 15ma||Octave||1586.31 : 884.36|
|2/3||Red dot||Just perfect fifth (3:2)||Just perfect fifth (3:2) 8va||Just perfect fifth (3:2) 8va||Unison||1901.96 : 701.96|
|5/7||Blue dot||Lesser septimal tritone (7:5)||Harmonic seventh (7:4) 8va||Harmonic seventh (7:4) 15ma||Octave||1782.51 : 582.51|
|3/4||Orange dot||Just perfect fourth (4:3)||2 octaves||2 octaves||Unison||2400.00 : 498.04|
|4/5||Yellow dot||Just major third (5:4)||Just major third (5:4) 15ma||Just major third (5:4) 15ma||Unison||2786.30 : 386.31|
|5/6||Green dot||Just minor third (6:5)||Just perfect fifth (3:2) 15ma||Just perfect fifth (3:2) 15ma||Unison||3102.00 : 315.64|
|6/7||Blue dot||Septimal minor third (7:6)||Harmonic seventh (7:4) 15ma||Harmonic seventh (7:4) 15ma||Unison||3368.80 : 266.87|
An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickups to convert the vibration of its strings into electrical signals, which ultimately are reproduced as sound by loudspeakers. The sound is sometimes shaped or electronically altered to achieve different timbres or tonal qualities from that of an acoustic guitar. Often, this is done through the use of effects such as reverb, distortion and "overdrive"; the latter is considered to be a key element of electric blues guitar music and rock guitar playing.
The guitar is a fretted musical instrument that typically has six strings. It is held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected strings against frets with the fingers of the opposite hand. A plectrum or individual finger picks may be used to strike the strings. The sound of the guitar is projected either acoustically, by means of a resonant chamber on the instrument, or amplified by an electronic pickup and an amplifier.
In music, just intonation or pure intonation is the attempt to tune all musical intervals as whole number ratios of frequencies. An interval tuned in this way is said to be pure, and may be called a just interval; when it is sounded, no beating is heard. Just intervals consist of members of a single harmonic series of an implied fundamental. For example, in the diagram, the notes G3 and C4 may be tuned as members of the harmonic series of the lowest C, in which case their frequencies will be 3 and 4 times, respectively, the fundamental frequency and their interval ratio equal to 4:3; they may also be tuned differently.
In music, there are two common meanings for tuning:
An overtone is any frequency greater than the fundamental frequency of a sound. In other words, overtones are higher pitches resulting from the lowest note or fundamental. While the fundamental is usually heard most prominently, overtones are actually present in any pitch except a true sine wave. The relative volume or amplitude of various overtone partials is one of the key identifying features of timbre, or the individual characteristic of a sound.
String instruments, stringed instruments, or chordophones are musical instruments that produce sound from vibrating strings when a performer plays or sounds the strings in some manner.
A fret is a space between two fretbars on the neck of a stringed instrument. Frets usually extend across the full width of the neck. On most modern western fretted instruments, frets are the spaces between the metal strips (fretbars) that are inserted into the fingerboard. On some historical instruments and non-European instruments, frets are made of pieces of string tied around the neck.
The fingerboard is an important component of most stringed instruments. It is a thin, long strip of material, usually wood, that is laminated to the front of the neck of an instrument. The strings run over the fingerboard, between the nut and bridge. To play the instrument, a musician presses strings down to the fingerboard to change the vibrating length, changing the pitch. This is called stopping the strings. Depending on the instrument and the style of music, the musician may pluck, strum or bow one or more strings with the hand that is not fretting the notes. On some instruments, notes can be sounded by the fretting hand alone, such as with hammer ons, an electric guitar technique.
A monochord, also known as sonometer, is an ancient musical and scientific laboratory instrument, involving one (mono-) string (chord). The term monochord is sometimes used as the class-name for any musical stringed instrument having only one string and a stick shaped body, also known as musical bows. According to the Hornbostel–Sachs system, string bows are bar zithers (311.1) while monochords are traditionally board zithers (314). The "harmonical canon", or monochord is, at its least, "merely a string having a board under it of exactly the same length, upon which may be delineated the points at which the string must be stopped to give certain notes," allowing comparison.
The tanpura is a long-necked plucked string instrument, originating from India, found in various forms in Indian music. It does not play melody but rather supports and sustains the melody of another instrument or singer by providing a continuous harmonic bourdon or drone. A tanpura is not played in rhythm with the soloist or percussionist: as the precise timing of plucking a cycle of four strings in a continuous loop is a determinant factor in the resultant sound, it is played unchangingly during the complete performance. The repeated cycle of plucking all strings creates the sonic canvas on which the melody of the raga is drawn. The combined sound of all strings, each string a fundamental tone with its own spectrum of overtones, supports and blend with the external tones sung or played by the soloist.
A prepared guitar is a guitar that has had its timbre altered by placing various objects on or between the instrument's strings, including other extended techniques. This practice is sometimes called tabletop guitar, because many prepared guitarists do not hold the instrument in the usual manner, but instead place the guitar on a table to manipulate it.
A multi-scale fingerboard is an instrument fretboard which incorporates multiple scale lengths. The scale length is the vibrating length of the strings.
An experimental musical instrument is a musical instrument that modifies or extends an existing instrument or class of instruments, or defines or creates a new class of instrument. Some are created through simple modifications, such as cracked drum cymbals or metal objects inserted between piano strings in a prepared piano. Some experimental instruments are created from household items like a homemade mute for brass instruments such as bathtub plugs. Other experimental instruments are created from electronic spare parts, or by mixing acoustic instruments with electric components.
Yuri Landman is a Dutch inventor of musical instruments and musician who has made several experimental electric string instruments for a number of artists including Lee Ranaldo of Sonic Youth, Liars, Jad Fair of Half Japanese, Liam Finn, and Laura-Mary Carter. Besides his musical activities he is also a graphic novel artist.
Playing a string harmonic is a string instrument technique that uses the nodes of natural harmonics of a musical string to isolate overtones. Playing string harmonics produces high pitched tones, often compared in timbre to a whistle or flute. Overtones can be isolated "by lightly touching the string with the finger instead of pressing it down" against the fingerboard.
String resonance occurs on string instruments. Strings or parts of strings may resonate at their fundamental or overtone frequencies when other strings are sounded. For example, an A string at 440 Hz will cause an E string at 330 Hz to resonate, because they share an overtone of 1320 Hz.
The 3rd bridge is an extended playing technique used on the electric guitar and other string instruments that allows a musician to produce distinctive timbres and overtones that are unavailable on a conventional string instrument with two bridges. The timbre created with this technique is close to that of gamelan instruments like the bonang and similar Indonesian types of pitched gongs.
A third bridge can be devised by inserting a rigid preparation object between the strings and the body or neck of the instrument, effectively diving the string into distinct vibrating segments.
The scale of harmonics is a musical scale based on the noded positions of the natural harmonics existing on a string. This musical scale is present on the guqin, regarded as one of the first string instruments with a musical scale. Most fret positions appearing on Non-Western string instruments (lutes) are equal to positions of this scale. Unexpectedly, these fret positions are actually the corresponding undertones of the overtones from the harmonic series. The distance from the nut to the fret is an integer number lower than the distance from the fret to the bridge.
A Home Swinger is a musical instrument created by Yuri Landman. The instrument has 12 strings, an electronic pickup and a movable rod to alter the pitch of the instrument.
Experimental luthiers are luthiers who take part in alternative stringed instrument manufacturing or create original string instruments altogether.