I've been concentrating on pitch and frequency for a few columns, and now it's time to move on to another key ingredient of great music: rhythm, and the element of time. As a transition I will mention the contrast between harmony and melody. Harmony is the simultaneous occurance of more than one note. Melody is the movement from one note to another through time. To me this is a fascinating part of music. It explores the fourth dimension: time. So synchronize your watches and here we go.

There's a bunch of stuff about time as it relates to music, but the one I'd like to concentrate on here is the effect which occurs when a sound is reflected back to the listener. We call these echoes, or early reflections, but when we think like guitar players we call them delays. There are lotsa pedals and effects rack toys that generate delays of our signals, so it would be cool if we had some understanding of how to use delays to our musical advantage.

Here's a rule of thumb regarding delays: If the time of the delay is set at less than 25 ms (1 ms = 1/1,000 second) the ear will not tend to hear that delayed sound as a seperate echo. So if you want to use a stereo delay device to fatten your guitar sound without adding an "echo" to it, set the left delay to 12-15 ms, and the right delay to 15- 20 ms. This will add a "room" sound to your guitar. Vary the delay settings, keeping them under 25 ms, and you can change the size of your imaginary room. How much high frequency you have on the reflections will determine how "bright" or "live" the room seems.

When you use a delay device to delay signals more than 25 ms, the ear hears the delayed signal as a seperate sound. If you delay the signal much more than that, a new aspect of the time element comes into play: tempo. Tempo is the rhythmic pulse of music, measured in beats per minute. If you play notes in tempo and have a delay setting that is a simple fraction of that tempo (250 ms = 1/2 of a beat at 120 bpm) then the rhythmic part of your playing is reenforced. This effect is often used on repetitive groove lines, and is very effective.

Try some combinations of these delay patterns. The variations are endless. Remember to use delays of less than 25 ms for "room" reflections, and longer delays for a tempo-like pulse. Next time, I'll apply this stuff to acoustic guitars, and then we'll see what happens when we change the delay time while the note is being played.

Have fun!

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