A slide is a finger device that temporarily takes the place of a fret; unlike a fret, a slide can be moved around freely. The use of slides could take the rest of this book to discuss completely, but this section will at least get you started. Playing with slides began with the blues. Early slides were bottle necks from beer bottles and small medicine bottles. Modern slides are made of glass or metal and are molded to perfectly match your finger; they come in different shapes and sizes to match every player. They run from around $5 to $10.
Because slides can move around “in between” the frets, they're great for imitating the voice, which naturally scoops and slides between the notes. The slide rests gently on top of the string, and like a harmonic, doesn't push down, but floats along the length of the string.
When playing slides, you have to determine what finger you want to place the slide on—middle, ring, or pinky finger. Most players use their middle or ring finger. You can't use the index finger because an essential part of slide playing is muting behind the slide to keep the strings quiet. If you put the slide on your index finger, you won't have a finger to mute with. Pick the finger that can reach all the strings comfortably.
Playing a slide can be great fun, but if it's not played in tune, no one will want to hear it. The fret takes care of the tuning for you, but when you play with a slide, the slide takes over for the fret. You have to control where the slide is on the string in order to tune the note. To get the slide in tune, you must be directly over the fret. Because this can be difficult, many slide players use back and forth vibrato motion to hide their tuning problems—which is fine and sounds vocal-like (shhh … that's why singers use vibrato, too).
The slide mimics your fretting hand, so you can use it on scales, single notes, and some chords, but because the slide is a straight line, it works only on a few chords. The slide is used for the blues scale almost exclusively. You can trace the scale shape with the slide in the same way that you play it with your fingers. Because the slide is straight across, you can jump to adjacent frets much easier than normal. When you use a slide, try to use it differently. Don't just recreate your old licks with a slide—try to create new ones that are not possible without the slide.
Alternate tuning implies that you are retuning the strings to anything other than standard E-A-D-G-B-E tuning. Alternate tunings are great for finding new chord shapes and unusual sounds that aren't possible on a standard tuned guitar. You will need a good chromatic tuner to help retune your strings. Here are three examples of some common alternate tunings:
• Drop-D tuning: Drop your lowest E string down one whole step to D.
The strings are then D, A, D, G, B, E. Drop D is useful for heavy music because it gives you some lower power chords. Power chords can be played with one finger. Look at FIGURE 13-1.
• “DADGAD” tuning: Tune your sixth string down to D, second string down to A, and first string down to D. Leave the others unchanged. This is a common tuning that can give you some unexpected results. Jimmy Page used this on “Black Mountain Side.”
• Open-E tuning: Tune the fifth string up to B, fourth string up to E, and third string up to G. Leave the others unchanged. Open-E tuning is a great slide tuning because you can play major chords with a straight slide played across one fret. It's also a nice tuning because your open strings make a nice-sounding E chord.
There are millions of other tunings, and you should try to invent new ones. Typically, alternate tunings are great for one song here and there, not for exclusive use. (But don't tell that to Joni Mitchell, who plays exclusively in open alternate tunings.)