Attached to the soundboard is a piece called the bridge, which acts as the anchor for one end of the six strings. The bridge has a thin, hard piece embedded in it called the saddle, which is the part that the strings rest against.
Attached to the soundboard is a piece called the bridge, which acts as the anchor for one end of the six strings. The bridge has a thin, hard piece embedded in it called the saddle, which is the part that the strings rest against.
A musical note is a tone. However, a musical-note tone comes from a small collection of tones that are pleasing to the human brain when used together. For example, you might pick a set of tones at the following frequencies:
This particular collection of tones is known as the major scale. Each tone in the scale is multiplied by a certain fraction to come up with the next tone in the scale. Here's how the major scale works:
Why are these particular fractions chosen in the major scale? Simply because they sound pleasing. Listen:
These particular tones have been given letter names, and also word names, like this:
Now the question becomes: How does a guitar generate the frequencies shown above? A guitar uses vibrating strings to generate tones. Any string under tension will vibrate at a specific frequency that is controlled by:
On a guitar, you can see that the different strings have different weights. The first string is like a thread, and the sixth string is wound so that it is much thicker and heavier. The tension on the strings is controlled by the tuning pegs. The length of the open strings, also known as the scale length, is the distance from the nut to the saddle. On most guitars, the scale length ranges from 24 inches to 26 inches. When you press down on a string at a fret you change the length of the string, and therefore its frequency when vibrating.
· The frets are spaced out so that the proper frequencies are produced when the string is held down at each fret. The magic number to use in positioning frets is 17.817. Let's say that the scale length for a guitar is 26 inches. The first fret should be located (26 / 17.817) 1.46 inches down from the nut, or 24.54 inches from the saddle. The second fret should be (24.54 / 17.817) 1.38 inches down from the first fret, or 23.16 inches from the saddle. The 12th fret should be exactly halfway between the nut and the saddle. The following table shows all of the fret positions and the frequency of each note on the first string (assuming a scale length of 26 inches).
· Table assumes scale length of 26 inches
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A musical note is a tone. However, a musical-note tone comes from a small collection of tones that are pleasing to the human brain when used together. For example, you might pick a set of tones at the following frequencies:
- 264 Hz
- 297 Hz
- 330 Hz
- 352 Hz
- 396 Hz
- 440 Hz
- 495 Hz
- 528 Hz
This particular collection of tones is known as the major scale. Each tone in the scale is multiplied by a certain fraction to come up with the next tone in the scale. Here's how the major scale works:
- 264 Hz * 9/8 = 297 Hz
- 297 Hz * 10/9 = 330 Hz
- 330 Hz * 16/15 = 352 Hz
- 352 Hz * 9/8 = 396 Hz
- 396 Hz * 10/9 = 440 Hz
- 440 Hz * 9/8 = 495 Hz
- 495 Hz * 16/15 = 528 Hz
Why are these particular fractions chosen in the major scale? Simply because they sound pleasing. Listen:
- Click here to hear the major scale. (At the dialog select, click "Open.")
These particular tones have been given letter names, and also word names, like this:
- 264 Hz - C, do (multiply by 9/8 to get:)
- 297 Hz - D, re (multiply by 10/9 to get:)
- 330 Hz - E, mi (multiply by 16/15 to get:)
- 352 Hz - F, fa (multiply by 9/8 to get:)
- 396 Hz - G, so (multiply by 10/9 to get:)
- 440 Hz - A, la (multiply by 9/8 to get:)
- 495 Hz - B, ti (multiply by 16/15 to get:)
- 528 Hz - C, do (multiply by 9/8 to get:)
Now the question becomes: How does a guitar generate the frequencies shown above? A guitar uses vibrating strings to generate tones. Any string under tension will vibrate at a specific frequency that is controlled by:
- The length of the string
- The amount of tension on the string
- The weight of the string
- The "springiness" of the string's material (a rubber band is a lot "springier" than kite string)
On a guitar, you can see that the different strings have different weights. The first string is like a thread, and the sixth string is wound so that it is much thicker and heavier. The tension on the strings is controlled by the tuning pegs. The length of the open strings, also known as the scale length, is the distance from the nut to the saddle. On most guitars, the scale length ranges from 24 inches to 26 inches. When you press down on a string at a fret you change the length of the string, and therefore its frequency when vibrating.
· The frets are spaced out so that the proper frequencies are produced when the string is held down at each fret. The magic number to use in positioning frets is 17.817. Let's say that the scale length for a guitar is 26 inches. The first fret should be located (26 / 17.817) 1.46 inches down from the nut, or 24.54 inches from the saddle. The second fret should be (24.54 / 17.817) 1.38 inches down from the first fret, or 23.16 inches from the saddle. The 12th fret should be exactly halfway between the nut and the saddle. The following table shows all of the fret positions and the frequency of each note on the first string (assuming a scale length of 26 inches).
Note
|
Fret
|
Frequency
(1st string) |
Fret position
from saddle |
E
|
open
|
329.6
|
26.00
|
F
|
1
|
349.2
|
24.54
|
F#
|
2
|
370.0
|
23.16
|
G
|
3
|
392.0
|
21.86
|
G#
|
4
|
415.3
|
20.64
|
A
|
5
|
440.0
|
19.48
|
A#
|
6
|
466.1
|
18.38
|
B
|
7
|
493.8
|
17.35
|
C
|
8
|
523.2
|
16.38
|
C#
|
9
|
554.3
|
15.46
|
D
|
10
|
587.3
|
14.59
|
D#
|
11
|
622.2
|
13.77
|
E
|
12
|
659.2
|
13.00
|
· Table assumes scale length of 26 inches
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