EBow is a brand name of Heet Sound Products, of Los Angeles, California, United States for the original type of monophonic handheld electromagnetic string driver, invented by Greg Heet in 1969, first introduced in 1976, and patented in 1978.
The EBow is a battery-powered electronic device for playing the electric guitar. The EBow uses a pickup - inductive string driver - feedback circuit, including a sensor coil, driver coil, and amplifier, to induce forced string vibrations. The EBow is monophonic, and drives one string at a time, producing a sound reminiscent of using a bow on the strings.
In 1976, Heet Sound introduced the first EBow at the NAMM Show. It featured an internal, string vibration triggered automatic power switch, a chromium-plated ABS plastic shell, a red LED power indicator, and a police-style form fitted black leather holster, embossed with the EBow logotype. In later years, five subsequent EBow models were introduced, all of which consisted of internal variations of the original EBow circuit and actuator coils, as well as color changes to the original plastic shell and EBow logotype, both of which remained essentially unaltered since the introduction of the EBow, with the exception of the addition of an external power switch on the back. The latest EBow model is the "Plus EBow", which is switchable between "standard mode" and "harmonic mode".
Since the 1990s, various manufacturers have introduced string drivers for guitar and bass, including hand held monophonic and polyphonic string drivers, as well as built-in and surface mounted types, commonly referred to as "Sustainers" or "Resonators", such as Fernandes Guitars (G-401), Sustainiac (Stealth Pro3), and "gooseneck" microphone stand mounted types (Vibesware Guitar Resonators).
The EBow is used to produce a variety of sounds not playable on a guitar using traditional strumming or picking techniques. These sounds are created by a string driver that gets its input signal by an internal pickup, which works like a guitar pickup. Its output signal is amplified and drives the other coil, which amplifies the string vibrations. With this feedback loop the player can create a continuous string vibration. Fading in and out by lowering and raising the EBow is also possible.
Starting with the current generation of EBow (PlusEBow, the 4th edition EBow), the user also gains an additional mode known as harmonic mode, which produces a higher harmonic sound instead of the fundamental note. This is achieved by reversing the signal phase to the driving coil, which damps the string's fundamental frequency and creates higher harmonics.
Many different artists have used the EBow in a wide variety of musical styles. One of the first notable users was Genesis guitarist Steve Hackett, who used the device on "Carpet Crawlers" from the band's 1974 album The Lamb Lies Down on Broadway. Other early pioneers of EBow playing were Chris Stein of Blondie and Max Sunyer, who used it in a 1978 live album Iceberg en directe, recorded and released in Spain. It was used later on by Bill Nelson, who introduced it to Stuart Adamson of The Skids. Adamson went on to use it with Big Country, specifically on the albums The Crossing, Steeltown, The Seer and Peace in Our Time. The EBow was a major contributor to the band's sound being labelled with the bagpipe tag, much to the frustration of guitarist Bruce Watson, who would also occasionally utilise the EBow. The EBow was utilized by Pink Floyd guitarist David Gilmour on the introduction to "Take it Back" on The Division Bell. In this case, it is possible that the sound produced stems from miking an un-amplified electric guitar, rather than from the more conventional amplified usage.
The EBow was used by Blue Oyster Cult lead guitarist Donald (Buck Dharma) Roeser, on their 1976 song, "(Don't Fear) The Reaper", to segue the middle instrumental lead break, back into the final verse of the song. The device was used again on the follow-up album, Spectres, on at least one track ("Celestial the Queen").
The EBow is frequently used by Radiohead guitarist Ed O'Brien in studio and for live performances of songs such as "Talk Show Host" and "Nude" and "My Iron Lung", "Where I End and You Begin" and the live version of "Jigsaw Falling into Place".
In the 1980s The Bongos used the EBow in the intro of their song "Numbers With Wings" and also in "River To River", "Miss Jean", "Glow", "Flew A Falcon" and "Sweet Blue Cage". Frontman Richard Barone continues to use an EBow on his subsequent solo recordings and much of his production work including his songs "Love is a Wind that Screams" and his cover of T. Rex's "The Visit". 
Besides its appearance in rock and jazz music, the EBow also made its way in the domain of contemporary art music, being used by John Cage in his harp piece A Postcard from Heaven (1982), Karlheinz Essl in Sequitur VIII (2008) for electric guitar and live-electronics, Elliott Sharp on SFERICS (1996), Arnold Dreyblatt in E-Bow Blues (1998) and David First in A Bet on Transcendence Favors the House (2008).
Although the EBow is most commonly played on the electric guitar, because of its ease of use and the responsiveness obtainable from the pickup, many artists have experimented with the EBow on other types of guitars and string instruments to various effect. While the EBow is not normally used with the electric bass guitar, which has heavier strings, Michael Manring (who uses light bass strings) uses it on his 1995 album Thönk. He has also been known to use two at once. Another instrument that the EBow is sometimes used on is the steel-string acoustic guitar. For example, guitarist David Gilmour of Pink Floyd used one on his Gibson J-200 acoustic in their 1994 song "Take It Back". Generally an acoustic guitar gives a limited response for varying reasons, including the density and spacing of the guitar strings. But despite these limitations, using an EBow on an acoustic guitar gives a rich, flute- and clarinet-like tone with a slow-swelling response.
Composer Luciano Chessa employs EBows regularly in his music for solo Vietnamese ?àn b?u. Furthermore, an EBow can also be utilised on a grand piano (with depressed sustain pedal) to create sustained sinusoidal sounds as it was used by Cor Fuhler in De Lamp, de Knijper en het Molentje (1991),Olga Neuwirth in Hooloomooloo (1997) and Karlheinz Essl in Sequitur XIII (2009) for extended piano and live-electronics.
This is a partial list of only notable performers who have used an EBow in at least three of their songs and who were not mentioned in the text above.