We have learned from textbook about beats. This learning object will focus on the application of beats on the violin tuning.

1. Beats, Chords
And
The Voilin

2. In our textbook, we have learned that “beat” is a
phenomenon that occurs when the frequencies of two
waves are different.
The figure below shows mathematically and graphically
of the two waves with different frequencies, and their
resultant wave. With this frequency difference, we can
see that the amplitude of the resultant wave changes
over time with a given period, and this is why we hear
“soft-loud-soft” beat pattern.

3. The violin has 4 strings, a violin player creates music by pressing fingers
on the fingerboard, as shown on the right image, and drawing the bow
on the lower part of a string to create vibration, as shown on the left
image.
The important thing to note here is that sometimes a violin player
presses and draws the bow on two strings simultaneously. This is
called CHORD.
This “beat” effect is used in many different
instruments. And this learning object will focus
on the violin. And here are some background
information that might be useful to know:

4. Most people know that when your violin strings are out
of tune, you use a “violin tuner” to adjust your violin back
to the right tune. A violin tuner is basically an electronic
device that checks if the frequency of each string matches
the correct frequency for each string.
However, there is an alternative approach to check if the
violin is in the right tune and this involves beats and
chords.

5. The four strings of the violin are actually called
E, A, D, and G, with their vibration frequencies
being 659.3Hz, 440.0Hz, 239.7Hz, and 196.0Hz,
respectively(when the strings are rightly tuned).
If you do some math, you will find that the ratios
of every two adjacent string frequencies(E and
A, A and D, D and G) are all approximately 3:2. In
music, this is called a “perfect fifth”.

6. Knowing this musical property, what a musician does is that they
would draw the bow on two strings simultaneously and hear the
sound it creates. By doing this, the musician creates a chord or a beat,
in terms of physics laws, since there is a frequency difference in two
strings. If the ratio of the frequencies of the strings is approximately
3:2, you would hear a pleasant and harmonic sound. However, if the
violin is out of tune, or the strings have wrong frequencies, the sound
it creates would not be nice to hear.
This is basically how musicians use the law of physics to tune their
instruments!!!

7. THANK
YOU!