Few instruments can evoke the qualities of a human voice as well as a slide guitar. An expert player can express a wide range of emotions, but the basic techniques of slide are accessible even to beginners... it starts with just one finger.
Before blues or country even existed, 19th century Hawaiian guitarists developed a style called slack key by tuning the open strings to a chord and playing changes by sliding up and down the neck with steel bars. Meanwhile, African Americans in the south had the diddley bow, a homemade, one-string instrument played with a bottle, knife, or even a piece of bone. In the early 20th century, these parallel traditions blended together to become the foundation of the blues, country, and rock slide guitar sounds we know today.
CHOOSING A SLIDE
Commercial slides are available in a variety of shapes and sizes; here are a few things to consider when making a choice:
• Material: Glass, steel, brass, copper and ceramic are the most common; the qualities are subtly different and the choice is a matter of taste.
• Weight: Medium weight and thickness— neither especially thin nor heavy— is easiest to manage.
• Length: about as long as the guitar neck is wide
• Diameter: just wide enough to slip over your finger up to the second knuckle (too loose and it can fly off).
• Finger: the explanations in this lesson are based on using the little finger, but every finger has its advantages, and many players prefer to wear the slide on their ring finger. Experiment before you decide.
A smooth slide sound depends on avoiding contact between the slide and the frets, so serious slide players favor heavy strings (some use flat-wounds to reduce string noise) and high action. However, if you switch between normal playing and slide within the same song, or if it’s simply not practical to dedicate a guitar to slide, you can make your everyday instrument work by developing a lighter touch and maybe using a clean boost pedal to fill out the sound.
HOLDING THE SLIDE
Holding your guitar normally, lay the slide flat across the strings, parallel to the frets. Rest the index (first) finger of your slide hand lightly on the strings, parallel to the slide about two frets below. Keep the second and third fingers slightly above the strings and position your thumb behind the neck opposite your first finger. Run the slide lightly along the strings and listen for a smooth, unbroken sound, with no bumps or scrapes from contacting the frets.
Slide guitar is essentially a fretless instrument, and playing in tune (intonation) depends entirely on your ability to hear and control minute differences in pitch. The first thing to notice is that when you fret a string it’s the fret itself, not your finger, that determines the pitch, so to match the same pitch with the slide you must position the slide directly over the fret. Practice intonation by fretting random notes and precisely matching each one with the slide.
A more musical way to practice intonation is to play melodies on one string. This is a common technique in down-home blues and gospel, where the slide is often played in unison with the voice. Classic examples include Blind Willie Johnson’s “Dark Was the Night, Cold Was the Ground” and Mississippi Fred McDowell’s “You Got to Move” (later covered by the Rolling Stones).
Ex. 1 is an unadorned melody on the high E string. Concentrate first and foremost on nailing each pitch as accurately as if you were fretting. Rest the slide lightly on the string and avoid contact with the frets. Pluck with either a bare finger or pick and mute the lower strings with the heel of your picking hand.
Ex. 2 “vocalizes” the same melody by sliding into notes and adding vibrato. For vibrato, rock the slide along the string on either side of the pitch, with your thumb behind the neck acting as a pivot. The width and speed of your vibrato are a matter of taste; contrast Tampa Red’s wide, sensuous vibrato (“Denver Blues”) with Muddy Waters’ fast, “buzzing” style (“Honey Bee”).
To phrase effectively while moving across the neck, you need to learn how to damp, i.e. control unused strings in order to prevent them from interfering with the melody. Some slide players prefer to pluck the strings with their bare fingers and others use a flatpick or thumbpick, often in conjunction with the fingers (hybrid picking), but whichever approach you choose, the goal is to connect the end of one note to the beginning of the next (legato phrasing) without overlapping. It takes persistence to develop consistent damping skills, but it’s an essential technique.
With the fingers: Place the slide over the ninth fret. Rest the heel of your picking hand on the lower strings near the bridge, with your thumb laying across the bottom three strings and your first, second and third fingers resting on the third, second, and first strings, respectively. Pluck the fourth string with your thumb, the third string with your first finger, second string with your second finger and first string with your third finger. As you pluck each string, move your thumb across the lower strings to act as a damper; when you descend, bring each bare finger back into position to damp the upper strings.
With a Pick: Mute the lower strings with the heel of your hand and the upper strings with your bare fingers. As you move across the strings from low to high, use the side of your thumb (which is holding the pick) to damp the lower strings; when you descend, drop the fingers back into position to damp the upper strings.
With either technique, practice moving back and forth from string to string to coordinate picking and damping, focusing on legato and avoiding overlap between notes.
If you use a slide only occasionally, playing in standard tuning is the most practical way to go. As slide icons Robert Nighthawk (“Sweet Black Angel”) and Earl Hooker (“Blue Guitar”) proved, it also has few limitations.
Classic slide melodies are organized around chord tones rather than scale or pentatonic box patterns, and in standard tuning the major barre chord with the root on the fifth string provides a good foundation. Ex. 3a shows the E7 chord tones between the ninth and 12th frets, and Ex. 4 presents some typical bluesy phrases within the same pattern (the rhythm track in the audio recording for this example includes an extra bar after each phrase, so that you can repeat it in tempo).
To play slide melodies over chord changes, a classic approach is to move the same note-pattern up or down the neck to match each chord; for example, build phrases around the ninth fret over the E chord, the 14th fret over A, and the 16th fret over B, as demonstrated in Ex. 5.
Tuning the strings to an open chord allows for one-finger changes and also makes accurate intonation a little easier by gathering frequently- used melody notes closer together. The most common slide open tunings are open G (known in Hawaii as taro patch and on the mainland as Spanish) and open D (a.k.a. Sebastopol or Vestapol).
OPEN G TUNING
Open G tuning was a favorite of traditional country blues artists, such as Charley Patton, Robert Johnson, and Muddy Waters. From standard tuning, tune the sixth, fifth, and first strings down a whole-step to form a G major chord (D-G-D-G-B-D, low to high). Open A tuning, a common variation, has the same layout, but up a whole step: E-AE-A-C#-E.
Ex. 6 illustrates the layout of G7 chord tones in open G tuning, and Ex. 7 is a 12-bar blues solo in G that includes double-stops (two notes at a time) and some “down-home” open-string phrases. Compare to versions of “Walking Blues” by Robert Johnson (on acoustic) and Muddy Waters (on electric).
OPEN D TUNING
The sound of open D tuning was epitomized by Elmore James; his performances on such classics as “Dust My Broom” and “It Hurts Me Too” inspired generations of blues and rock slide players with raw power and emotional expression.
Open D places the root of the chord on the top string, so phrases tend to resemble those of standard tuning more than they do in open G. From standard tuning, tune the first, second, and sixth strings down a whole step and the third string down a half-step (D-A-D-F#-A-D, low to high). Open E tuning, which has the same layout a step higher (E-B-E-G#-B-E), was favored by Duane Allman and carried on by his virtuoso disciple, Derek Trucks.
Ex. 8 shows the layout of D7 chord tones in open D tuning, and Ex. 9 is an eight-bar solo in the style of “It Hurts Me Too” and built around the same pattern with a focus on vocal expression. An extra benefit of learning slide is that you return to your normal style with a deeper awareness of the importance of each note.
In the words of Derek Trucks, “[Slide guitar] can sound like the most beautiful woman in the world or like somebody skinning a cat.” Virtuoso slide players like Trucks have developed techniques that go far beyond the scope of this introductory lesson, but slide rests first and foremost on the foundation of precise pitch and an ear for melody. It only takes one finger, but when you land that finger just right, it’s magic.