Things a Guitar Can Do That a Piano Can’t

After many years of playing guitar, I recently started teaching myself piano. It has been a challenge and great for reminding me what it was like to first learn guitar. I'm already seeing how learning piano will help my guitar playing.

The piano is a really powerful instrument. With ten fingers, you can play ten notes at once, or more if you use the sustain pedal or you mash two keys with one finger. It can play both higher and lower than a guitar - at the same time! Unplugged, a piano is louder. And there is tons and tons of music for the piano - a lot of it classical, but going through ragtime, jazz, some blues, and even some rock.

That got me thinking. Why is the guitar the indisputable queen of instruments in today's popular music? Folk, blues, and especially rock and roll? What is so special about the guitar that makes it so perfect for rock? I love Billy Joel's music, and Jerry Lee Lewis kicked ass, but numbers-wise, guitarists leave pianist in the dust. Why is that?

Well, first of all, we have the practical considerations. Pianos are big, heavy, and expensive. Guitars are cheap and portable. That's obvious, but I think there's a lot more to it than that. After all, ragtime was not a rich-man's music. It's not too hard to find a piano to play, even if you can't afford your own. No, there has to be something about the sound of the guitar, something about what you can do with it.

And here it is

This is my list of things a guitar can do that a piano can't. This is not intended to diss pianos, or to even say one instrument is better than another. No, it's more of a thought-experiment, a reminder of just what it is that makes the guitar such a special instrument. A good guitarist should be aware of all these techniques and take advantage of them whenever it fits the song. Otherwise, you might as well be playing piano.

Note that I'm limiting this discussion to acoustic guitars and pianos. Once we start getting into the electronic keyboards and electric guitars, it becomes a whole different ball game, with all the special effects and so on. I'm keeping this just to the basic, primitive instruments.

String bends
When you hit a piano key, once the key is down there is nothing you can do to change the sound. The note sounds the same pitch until you let up the key or the pedal. With a guitar, you can bend up to a note, you can unbend down to a note, you can hit a note a quarter step up, you can bend up then down, or down then up.
Because of this, a guitar can actually play more notes than a piano, even if a piano has a larger range. Bending gives us the infinity of "notes between the notes."
It also can give a great wailing sound. Listen to any solo by Kirk Hammett of Metallica or David Gilmour of Pink Floyd, and I guarantee at least half of the notes are played with a string bend of one sort or another. It's the sound of the blues, and by extension, the sound of rock'n'roll.
This is related to string bends, but more subtle. The vibrato is where a guitarist really shows his personality. Think of B.B. King, the quintessence of distinctive vibrato. You can tell after one note that you're listening to the King when you here his trademark "bee-sting" sound.
It also brings the sound of the guitar closer to that of the human voice. Studies have shown that we are psychologically hard-wired to respond emotionally to the sound of another person's voice. That's why, historically, the most popular instruments are the ones that come closest to singing. (That's also why I can't stand the recent Auto-Tune craze. But that's for another post.) If you can make your guitar sing, my friend, then you have truly mastered your instrument.
Varying string attacks
Hitting a piano key, you can hit it hard, you can hit it soft. You can hit it very hard, or very soft, or somewhere in between.
When you pluck a guitar string, you can do all that, plus a whole lot more. When you play with a pick, it sounds different than when you play with your fingers. A string plucked with your thumb will have a different sound than one plucked with your index finger. An upstroke sounds different from a downstroke. You can use different styles of pick. You can play with the side of your pick. You can play with the edge of your pick. You can play with your fingernail. You can play with the fleshy part of your finger. You can play near the bridge, you can play near the soundhole, you can play way up on the fingerboard.
The possibilities are literally endless. Beginning guitarists don't think too much about these aspects, but they can make a huge difference in the sound. Especially in acoustic fingerpicking, they can show the difference between an amateur and a real pro.
Snapping the strings
This technically belongs in the last category, but I decided to list it separately because it doesn't get enough attention. What I'm referring to is when you pull the string away from the body of the guitar, then let it snap back against the fretboard. This produces a loud percussive sound, but with pitch. It can be the perfect thing to liven up some playing, especially when you do it on the low E string. And don't be afraid to put some oomph into it. Trust me, you won't break the string, but you'll definitely attract some attention.
Hammer-ons and pull-offs
When you want that smooth, legato, sound, nothing is quite like a hammer-on or a pull off. Just take the sound of the pick right out of the equation.
Slide up. Slide down. Slide fast. Slide slow. Slide one note at the beginning of a solo. Slide a whole chord at the end. The possibilities are endless.
Mute your strings with your left hand and strum a bit, and all of a sudden you're your own rhythm section! Dave Matthews uses this technique a ton.
There's nothing like the sweet sound of pure overtones. Just lay your finger lightly on a string at the fifth, seventh, or 12th fret, pluck, and you're on your way to harmonic bliss.

Well, the list goes on, but that ought to stoke some creativity. It's a pretty cool instrument we've taken up. But only if you take advantage of everything that makes it unique.