Slide Guitar - Equipment

Equipment

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:

• All steel guitars.
• Many (perhaps most) resonator guitars, particularly Dobros and their descendants.
• Lap slide guitars, particularly Weissenborns and their descendants.
• Conventional electric guitar.

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.

Approximately in 1975, glass guitar slides started appearing in Music shops across America. Clear Glass Manufacturing Company and Clayton Products supplied the majority of the market. Both companies grew, though eventually Clear Glass was sold to Dunlop Manufacturing. Borosilicate glass (Pyrex) was developed by Corning Glass Works. Modern bottleneck slides are still manufactured by companies such as Dunlop Mfg., Steve Clayton, Inc., Mr. B's Bottleneck Guitar Slides, Bluemoon Bottleneck Company and Diamond Bottlenecks.

A slide can be made with any type of smooth hard material that allows tones to resonate. The slide's weight (in terms of density and wall thickness) cause differences in sustain, timbre, and loudness, while the surface structure and material affect tonal clarity and timbre. Heavier bottlenecks usually can produce longer, warmer and louder tones, but they also require more mastery to play with.

With the sliding technique originating from the cut off neck of a glass bottle, bottlenecks usually still have the same tubular shape and a length of one to three inches, and glass still remains a popular material. Borosilicate glass is often found in cheaper, entry-level slides. It is easier to shape as it can withstand higher temperatures. Soda-lime glass is heavier which helps produce a better sound, while lead glass improves tonal quality. Glass coloring alters the timbre. The addition of iron oxide turns glass green and hardens it, causing a louder and sharper tone with a warmer sustain, while cobalt oxide colors it blue and produces the sharpest, loudest tones. The structural properties of colored glass promote withstanding mechanical shock, which allows for automated manufacturing.

In 1989, Terrie Lambert invented the Moonshine (ceramic) slide that produces a timbre in between that of brass and glass, and the Mudslide (porcelain) slide, which just as brass slides is quite heavy, producing richer, fuller and resonating tones with more harmonics. As a result, they are often used in blues music. The Moonshine and Mudslide slides are glazed on the outside but porous on the inside so that finger moisture is absorbed, preventing slippage. Metals such as stainless steel, chrome and aluminium cause a bright penetrating sound and are mostly used with electric guitars, among others for rock music. Less frequently used types of materials include stag antler, buffalo horn and bone, as the time and effort needed to create one is often too much when conventional slides are available. Segments of PVC piping can be used to achieve a slide, and is common among those who do not choose to buy a slide.

Besides differences in material, many variations in bottlenecks exist. Square, beveled or rounded edges may allow a player to apply different techniques, while tapered rather than straight sides may help improve control and cause less damping. Pedal steel players may prefer using tonebars, which have one capped end. One recent development is the rise of hybrid slides. Glass Moonshine slides are made of glass, but have a porous ceramic interior that helps prevent slipping; other slides have been designed to reduce the weight of brass or porcelain slides by using a lightweight interior, while still others are made of glass on the front and of metal on the back to allow easy switching.

Although the use of hollow bottlenecks is preferred by many players because only one finger is required to hold it, leaving the other fingers free for normal fretting, sliding can be done in many ways. One alternative is to use a solid metal bar or rod, about the same size as a bottleneck slide, 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. Even a knife can reportedly be used:

"As he played, he pressed a knife on the strings of the guitar in a manner popularised by Hawaiian guitarists who used steel bars. The effect was unforgettable." ―W. C. Handy on his first hearing slide guitar, a blues player in the Tutwiler, Mississippi train station.