In the 1970s and 1980s Mike Rutherford of Genesis was known for playing a custom-made Shergold Modulator twin-neck guitar-bass unit in live shows, as he frequently changed between lead guitar, 12-string guitar and bass guitar, depending on the arrangement of the song. The unique design concept of Rutherford’s Shergold guitar set is that it consists of several interchangeable modular elements, each of which could be separated and recombined, and which attached to the other units through a system of dowels and thumbscrews, and an electrical connector. The complete original set consisted of a “top section” 6-string guitar, two “top-section” 12-string guitars (each in a different tuning), and a “bottom-section” 4-string bass. Each section could be separated and re-attached to create a variety of twin-neck combinations, with either the 6-string or one of the two 12-strings on the top, and the 4-string bass on the bottom, and there was a matching lower-body section which could be attached to the 6-string and 12-string main units, which created a single complete guitar when these were not attached to the bass. (As a tongue-in-cheek reference to this, the puppet version of Rutherford in the video for Land of Confusion plays a four-necked guitar.)
 Multiple-necked bass guitars
Guitar makers have been producing bass guitars with multiple necks at least since the 1970s, the majority having two necks. There are some basses with three or more necks made, but usually upon custom order only. A double-necked bass guitar can be used for multiple tuning (e.g., B-E-A-D on one neck whilst the other neck is tuned to E-A-D-G, etc.); combining fretted and fretless necks; combining necks with different numbers of strings, etc.
One of the more well-known multiple-necked bass guitars is that used by Chris Squire (of Yes) for the song “Awaken.” This is a replica of a guitar built by Wal for Roger Newell of the English Rock Ensemble. Squire’s original triple-necked bass guitar was configured with a four-string fretted neck, a four-string fretless neck, and a six-string tuned in octaves (Squire was known to have tuned it to aA-dD-gG). This bass is currently on display at the Hard Rock Cafe. Steve Digiorgio used a multiple-necked bass guitar with a fretless neck and another fretted neck. A number of makers have also produced double neck basses with an 8-string bass neck (double courses, tuned in octaves like a 12-string guitar) on top and a 4-string bass neck on the bottom. Double neck basses with various other combinations exist, for example: four string and five string bass; four string and six string bass; etc.
Multiple neck “guitars” have also been made which include other stringed instruments among the alternate necks. Country guitarist Joe Maphis famously played a double-neck Mosrite instrument that had a regular 6-string neck on the bottom and an “octave guitar” for the top neck. This was a 6-string neck tuned an octave higher than the standard guitar, that both extended the range of the instrument, and allowed Maphis to play mandolin-like sounds. Between 1958-1968, Gibson made an instrument of this type which it called the “Double Mandolin” (Gibson EMS 1235). Hybrids with a 6-string guitar neck and a true 8-string mandolin neck were also made (e.g., the 1971 Dawson Electric guitar/mandolin). And Led Zeppelin’s John Paul Jones has a triple-neck electroacoustic instrument, custom made for him by luthier Andy Manson, which features (from top to bottom) 8-string mandolin, 12-string guitar, and 6-string guitar necks.
Pro Electric has produced a quadruple-necked instrument some have called the “ultimate blugrass axe,” not entirely without sarcasm. This solid-body electric instrument combines 6-string guitar, 4-string bass, 8-string mandolin, and 5-string banjo necks into one (heavy) package.
Canadian country music star Steve Puto owns a five-neck instrument that includes guitar, bass, banjo, mandolin, and fiddle necks—with a harmonica mounted on the fiddle body, for good measure. Puto says he found the instrument (which bears no maker’s name) in 1973 in a friend’s music shop, and he played it regularly on his TV show (The Lonesome Steve Show) in the 1970s.
In 2011, the National Guitar Museum unveiled the “Rock Ock”, which it calls the world’s largest fully playable multi-necked stringed instrument. The 8-necked guitar weighs 40 pounds, has 154 frets, 51 strings, and 8 necks. The eight instruments are a mandolin, ukulele, 6-string, fretless bass, standard bass, 12-string, baritone guitar, and a 7-string. The guitar was designed by noted artist Gerard Huerta (responsible for the iconic AC/DC logo, among others) and built by Dan Neafsey of DGN Custom Guitars. The guitar hardware was supplied by Mojo Musical Supply while the instrument itself was commissioned by The National GUITAR Museum. The instrument has been used in live performance and can be seen on YouTube.
 Experimental alternate versions
Some luthiers not only built guitars with two necks in common configurations, but worked to expand the possibilities with multiple necks, extra bridges, odd configurations, and the like. Hans Reichel crafted a series of third bridge guitars with two necks on both sides of the body. Linda Manzer crafted the Pikasso guitar (a three neck guitar with 42 strings) for Pat Metheny. Solmania is an Osaka-based noise music band known for making their own experimental electric guitars out of spare parts. The guitars usually take an extremely bizarre form, utilizing unconventional body shapes, extra necks, strings and pickups in unusual places, and various extraneous gadgets such as microphones. Most of their instruments are double neck guitars or harp guitars.
 Potential limitations
Many of those who have played double neck guitars report that the instruments are heavy and awkward, but this can be managed with practice. Triple neck instruments are even weightier and more unwieldy. This raises the question as to whether some of the larger varieties of multi-neck guitar are even playable as guitars, much less practical in performance situations. The bottom neck of Rick Nielsen’s famous five-neck Hamer guitar is barely reachable by a person of average stature holding the instrument in a normal standing playing position, and it’s hard to see how that neck could be played with any facility with both arms extended to their limit just to reach it. (Indeed, Nielsen himself hardly ever plays on that neck.) Although playable hybrids with up to eight necks have been produced (see the “Rock Ock”, above), five necks would seem to be the practical limit for multi-neck guitars.
Luthiers seem, however, to be undeterred by either practicality, or by the limits of human anatomy, and have produced instruments with even more necks. In 2008 Macari’s Music of London commissioned a six neck guitar (“the beast”), similar in design to Nielsen’s five neck. Yamantaka Eye, of the Japanese noise/rock band Boredoms has toured with a seven neck guitar (the “Sevena”). This instrument has four necks on one side and three on the other, and is mounted on a stand and played with drumsticks as a percussion instrument.
As of 2012, the most necks placed on a single guitar is 12, apparently first achieved in 2002 by Japanese artist Yoshihiko Satoh.