Slide guitar or bottleneck guitar is a particular method or technique for playing the guitar. The term slide is in reference to the sliding motion of the slide against the strings, while bottleneck refers to the original material of choice for such slides, which were the necks of glass bottles. Instead of altering the pitch of the strings in the normal manner (by pressing the string against frets), a slide is placed upon the string to vary its vibrating length, and pitch. This slide can then be moved along the string without lifting, creating continuous transitions in pitch.
Slide guitar is most often played (assuming a right-handed player and guitar):
Slides may be used on any guitar, but slides generally and steels in particular are often used on instruments specifically made to be played in this manner. These include:
Since the introduction of slide guitar playing in the early 1900s, many different materials have been used to play slide guitar. Various smooth hard objects may be used as a slide. One of the most common is the neck of a glass bottle, which is slipped over one of the fingers of the fretting hand. The term "bottleneck guitar" derives from this. A glass, stainless steel, brass, or chrome tube of approximately the same size (typically one to two inches long and ¾ inch diameter) may also be used. There are also the Mudslide porcelain and Moonshine Slides ceramic slides, invented by Terrie Lambert in 1990, which are glazed on the outside but porous on the inside, so that finger moisture is absorbed, preventing slippage. Technically a slide can be made with any material, so long as it resonates, and the craftsmanship is good. Examples include stag antler and buffalo horn, although slides like these are not often sold in mainstream shops, if at all, as the time and effort needed to create one is often too much when conventional slides are available. An alternative method is to use a solid metal bar or rod, also about the same size as above, laid across the strings of the guitar and held by the fingers of the fretting hand being laid on it to either side, parallel to it. Shotglasses, pipes, and stones have also been used to good effect, as have rings, spoons and even cigarette lighters.
One can also use a knife instead of a bar:
An ordinary guitar, either electric or acoustic, can be used for playing slide. Often the strings are raised a little higher off the neck than they would be for ordinary guitar playing. This is done especially if the free fingers are not going to be used for fretting. An extension nut may be used to achieve the higher string height at the peghead end of the neck. This is just a normal nut, with the slots filed less deeply, and often in a straight line rather than following the radius of the fretboard.
The lap steel and the pedal steel are guitars that have evolved especially for playing slide in the horizontal position. Resophonic or resonator guitars have often been employed for slide playing, typically held horizontally. They are sometimes known as dobros after the Dopyera brothers, whose company first made them. National is another brand. In resonator guitars, rather than the sound being produced by the body's hollow, a special bridge transfers the vibrations from the strings to a metal cone placed inside the body.
The slide is pressed against the strings—lightly, so as not to touch the strings to the fretboard, and parallel to the frets. The pitch of the strings can then be continuously varied by moving the slide up and down the neck. The usual limitation in fretted guitar playing of twelve pitches per octave does not apply. Indeed, in pure slide guitar playing the frets serve no purpose, other than as a visual reference. The technique lends itself to glissandi (swoops up or down to a note); in addition it has the ability to evoke sounds of the human voice, crying, sighing or weeping, or natural noises. Another strength of the technique is its vibrato, which is easily achieved by oscillating the hand so that the slide goes quickly back and forth.
The major limitation of slide playing is of course that only one chord shape is available: whatever the strings happen to be tuned to going straight across. Many slide guitarists will still use their free fingers to fret the strings if they want to employ that sound as well. Using the free fingers opens up the possibility of playing chord shapes other than the straight line given by the slide. One strategy is to use the free fingers for rhythm work, and intersperse this with lead phrases played with the slide.
The guitar may be held in the normal guitar-playing position (that is, with the face of the guitar more-or-less vertical) or it may be held flat, with the face of the guitar horizontal. In the latter case the guitar may sit flat in one's lap or on a stool, face up, or held in this position by a strap, and played standing up. If holding the guitar in the normal vertical position, it is more common to use the tube type of slide. In the horizontal approach, solid bars or "bullets" are more commonly used, and the grip is overhand: the hand is not wrapped around the neck, the index finger is nearest the bridge, the little finger nearest the nut, fingers pointing away from the chest.
Usually, a slide player will use open tuning, although standard tuning is sometimes used. In open tuning the strings are tuned to sound a chord when not fretted; sliding the bottleneck up and down the guitar neck gives that chord in various keys. The chord tuned to is most often major. Open tunings commonly used with slide include Open D or "Vestapol" tuning: D-A-d-f#-a-d; and Open G or "Spanish" tuning: D-G-d-g-b-d . Open E and Open A, formed by raising each of those tunings a whole tone, are also common. These tunings can be traced back to the 18th century through the banjo, predating the Hawaiian guitar. Another open D tuning is D-A-d-a-d-f#. Other tunings are used as well.
Occasionally a bottleneck is used on only the highest two strings of a guitar in standard tuning, usually in live performance to introduce just a short passage of bottleneck effect into a piece which otherwise consists mainly of guitar played in standard fashion.
Slide guitar is most often fingerpicked, with or without plastic or metal picks on the thumb and fingers. However some players use a flatpick (plectrum).
The bottleneck or tube type of slide is usually worn over the ring (3rd) or little (4th) finger. Wearing it on the 4th finger has the advantage of leaving one more finger free to fret notes if desired. However some players feel that they get better control using the ring finger. Most instructors recommend letting one or more of the fingers behind the slide rest lightly on the strings to help mute unwanted vibrations.
The main technical challenges with slide guitar playing are:
Slide guitar places greater demands on one's ability to mute strings than standard guitar does. Playing a melody with well articulated individual notes requires more skill than may at first be apparent; it is easy to get a howling mass of notes on slide guitar until muting is mastered. This is because the movement of the slide, which is usually pressing down more than one string, causes those strings to sound, but not all of those strings are necessarily intended to sound at a given time. In contrast to fretting, in which the note decays quickly after the fretting finger is lifted, unwanted notes while using a slide must be actively muted. One can touch the string with a fingertip of the picking hand, or lift the slide and damp with a fretting-hand finger. The first method is more selective, the second stops all sound.
A relatively new technique, expanding the musical range and sonic capabilities of slide guitar, is the system of double slide guitar. It was invented by Brian Cober, a Canadian blues musician. In double slide, the first slide is placed on the middle finger (usually a modified steel bar that can be put on the finger) and a modified thumb slide is put on the thumb that is able to cover two strings. Double slide is meant to be played on a six string lap guitar (or a regular six string guitar modified with the strings raised up for high action like a lap guitar), usually tuned to open e tuning. The double slide guitar system allows for the player to achieve chords not heard in open tunings, such as minor chords, dominant seventh chords etc. and allows for a greater use of technique in soloing. Will Ray of the Hellecasters uses a similar technique, wearing "stealth" pinky type slides on either hand.
The technique of using a slide on a string has been traced to a one-string toy-instrument: the "diddley bow," which resembles one-stringed African instruments. The tuning and bend filled playing style resembles the blues-harp. While this seems to imply that the technique originated in Africa and crossed the Atlantic during the slave trade, there is also a Pacific connection (the Hawaiian "slack guitar style"), possibly tracing its origins back to the Indian subcontinent, where the Vichitra Veena is played sliding a glass ball across the strings.
The technique was made popular by African American blues artists. The first musician to be recorded using the style was Sylvester Weaver who recorded two solo pieces "Guitar Blues" and "Guitar Rag" in 1923. Some of the blues artists who most prominently used the slide include gospel singer Blind Willie Johnson, Blind Willie McTell, Mississippi Fred McDowell, Son House, and Robert Johnson as well as Casey Bill Weldon of the Memphis Jug Band. The sound has since become commonplace in country and Hawaiian music. It is also used in rock, by bands such as The Allman Brothers Band, Lynyrd Skynyrd, Led Zeppelin, Pink Floyd (whose original singer Syd Barrett used a Zippo rather than an actual slide on the song See Emily Play), and ZZ Top that have been heavily influenced by the blues. While the Allmans were the first to bring slide guitar to a wide audience, The Rolling Stones used it as early as their 1963 recording of the John Lennon/Paul McCartney song "I Wanna Be Your Man". Guitarist Brian Jones played slide in a very blues-oriented style. His successor, Mick Taylor also displayed his own slide guitar skills while with the band, using a bottleneck on studio recordings and during live performances.
Arguably the first influential classic electric blues slide guitarist is Elmore James, whose riff in the song "Dust My Broom" is copied from Robert Johnson and is held in particularly high regard. Blues legend Muddy Waters was also very influential, particularly in developing the electric Chicago blues slide guitar from the acoustic Mississippi Delta slide guitar. Texas bluesmaster Johnny Winter developed his distinctive style through years of touring with Muddy. Slide player Roy Rogers honed his prodigious skills by touring with blues giant John Lee Hooker. John Lee's cousin, the great Earl Hooker, may have been the first to use wah and slide together.
Duane Allman played a key role in bringing slide guitar into rock music, through his work with the Allman Brothers Band. Duane Allman shows his skill in playing slide guitar in the 1971 live album At Fillmore East and with Derek and the Dominos' Layla and Other Assorted Love Songs album. Beginning in the late 1960s, Allman used an empty glass Coricidin medicine bottle, which he wore over his ring finger, as a slide; this was later picked up by other slide guitarists such as Bonnie Raitt, Rory Gallagher, and Gary Rossington of Lynyrd Skynyrd. Such bottles eventually went out of production in the early 1980s (although replicas have been produced since 1985).
Duane extended the expressive range of the slide guitar by incorporating the harmonica effects of Sonny Boy Williamson II, most clearly in the Allman Brothers' cover version of Sonny Boy's One Way Out, heard on their CD Eat a Peach. He made his slide playing sound remarkably like an alto saxophone in the ABB's live version of "You Don't Love Me" on their 1989 anthology Dreams. (During his solo he included a portion of the song "Soul Serenade" as a tribute to his close friend, the then-recently-murdered alto player King Curtis.)
Bonnie Raitt also showcases the slide guitar, much like her long-time friend and slide guitarist, Lowell George (using an 11/16 spark plug socket), as well as studio and solo artist Ry Cooder and George Harrison.
Modern examples of slide guitar play include: Eric Sardinas, Dan Auerbach of the The Black Keys,Joe Bonamassa, Beck Hansen, Derek Trucks, Ben Harper, Warren Haynes and Rich Robinson have also become a prominent slide guitarists in modern rock music.