This is the final discussion about a most important element of musical expression: frequency. Last time I mentioned that a single guitar note is composed of many frequencies (overtones), which are naturally occuring multiples of the note itself (the root). Now that we understand the principle, let's see how to control these multiple vibrations, which we call the TONE of the note.

Usually, the higher the overtone, the quieter it is in relation to the Root. Last time we noticed that by plucking the string closer to the bridge, more overtones are heard in relation to the root. But now check this out: let's say you pick a note exactly one-quarter of the way from the bridge to the fingered fret. This will accent the overtone whose frequency is twice that of the root. Play twice as close to the bridge and the pick will accent an overtone that is one octave higher. Don't worry about the numbers, but realize that picking closer to the bridge "brightens" the tone by accenting higher overtones.

Since the ratio of overtones to the root determines the tone of a note, then the following must be true: To keep the tone of a series of notes the same, the same string should be picked closer to the bridge as higher frets are played with the other hand. Why? Of course, to preserve the ratio we talked about above. This stuff may not seem obvious at first, but try it on your guitar by playing up and down the guitar neck on a single string, while always picking in the same spot. You'll notice that the higher notes sound duller in tone than the lower notes, and that's why: You are changing the overtone to root ratio.

This also explains an important part of electric guitar design, the placement of the pickup. I bet you can figure out at this point that a pickup placed closer to the bridge will have a "brighter" tone because it picks up more of the higher overtones of a note. So with no stompboxes at all you can get a huge variety of tones on an electric guitar by choosing your picking point wisely. And yes, things like larger string size and pointier picks also accent overtones for a brighter sound.

Speaking of stomp boxes, let's mention the mid-frequency booster that moves: the Wah-Wah. That's all a Wah-Wah does, really, is to accent a narrow band of midrange frequencies (usually 500 hz to 1,500 hz) and allow you to change the point of accent up or down. Remember that Wah- Wahs don't follow or maintain overtone relationships. They focus on their given point regardless of what note or tone you're playing. That's why really good players of the Wah choose their notes so the Wah-Wah's effect really accents the right overtones. Try rocking a Wah-Wah pedal to a certain point and stopping. Then find which notes sound the most or least different in tone. It seems tedious, but goofing around like that can really improve your control over frequencies, overtones, and music.

Next time, a journey into the fourth dimension.

Good tone to alll......

Fred Bogert is the proprietor of Studio C in Nashville, which also manages the historic RCA Studio B.