The physics of playing guitar - Oscar Fernando Perez

譯者: 曾 致彥 審譯者: 旻霏 郭

Hendrix, Cobain and Page.

亨德里克斯，柯本和佩奇 （均為傳奇吉他手）

They can all shred,

他們都能速彈

but how exactly do the iconic contraptions in their hands

不過他們手上的玩意兒是如何

produce notes, rhythm, melody and music.

產生音符、節奏、旋律和音樂

When you pluck a guitar string, you create a vibration called a standing wave.

當你撥弦時，產生了振動叫做駐波

Some points on the string, called nodes, don't move at all,

弦上的某些點叫做波節，完全不動

while other points, anti-nodes, oscillate back and forth.

弦上還有某些點叫做波腹 會來回振盪

The vibration translates through the neck and bridge to the guitar's body,

這個振盪通過琴頸和琴橋傳遞到琴身

where the thin and flexible wood vibrates,

琴身細而有彈性的木頭振動

jostling the surrounding air molecules together and apart.

將周圍的空氣分子攪動得聚集又分開

These sequential compressions create sound waves,

這些連續的擠壓產生了聲波

and the ones inside the guitar mostly escape through the hole.

吉他內部的聲波 大部分從洞中散播出來

They eventually propagate to your ear,

它們最終傳播到你的耳中

which translates them into electrical impulses

耳朵將它們翻譯為電脈衝

that your brain interprets as sound.

你的大腦將它們轉為聲音

The pitch of that sound depends on the frequency of the compressions.

聲音的音調由壓縮的頻率決定

A quickly vibrating string will cause a lot of compressions close together,

快速振動的弦會讓壓縮聚得更攏

making a high-pitched sound,

造成高音調的聲音

and a slow vibration produces a low-pitched sound.

慢速的振動產生低音調聲音

Four things affect the frequency of a vibrating string:

四個因素影響弦振動的頻率

the length, the tension, the density and the thickness.

長度、張力、密度和厚度

Typical guitar strings are all the same length,

普通的吉他弦長度都相同

and have similar tension, but vary in thickness and density.

並且有相似的張力 但是密度和粗細不同

Thicker strings vibrate more slowly, producing lower notes.

粗一些的琴弦振動得比較慢 彈出的音符音調低

Each time you pluck a string,

每次撥動琴弦的時候

you actually create several standing waves.

其實是在創造好幾個駐波

There's the first fundamental wave, which determines the pitch of the note,

其中有第一個基波，能決定音高

but there are also waves called overtones,

但是也有叫做泛音的波

whose frequencies are multiples of the first one.

它的頻率是第一個波的好幾倍

All these standing waves combine to form a complex wave with a rich sound.

所有的駐波合在一起 就組成一個複雜的波

創造出濃厚的聲音

Changing the way you pluck the string affects which overtones you get.

改變撥動琴弦的方式 能影響你創造的泛音

If you pluck it near the middle,

如果你在中間撥動琴弦

you get mainly the fundamental and the odd multiple overtones,

你聽到的只有基波和奇數組的泛音波

which have anti-nodes in the middle of the string.

泛音波在弦的中間有波腹

If you pluck it near the bridge, you get mainly even multiple overtones

如果你在琴橋撥動琴弦 你聽到的主要是偶數組泛音波

and a twangier sound.

和彈撥的弦聲

The familiar Western scale is based on the overtone series of a vibrating string.

我們所熟悉的西方音樂中的音階 就是基於琴弦振動時的泛音

When we hear one note played with another that has exactly twice its frequency,

當我們聽到一個音符的振動頻率 正好是另一個音符的兩倍時

its first overtone,

就是它的第一個泛音

they sound so harmonious that we assign them the same letter,

它們聽上去如此和諧 我們給它們相同的字母

and define the difference between them as an octave.

並且把它們之間的距離叫做一個八度

The rest of the scale is squeezed into that octave

音階中剩餘的音符都在一個八度中間

divided into twelve half steps

分成十二個半音

whose frequency is each 2^(1/12) higher than the one before.

每一個音符的頻率都比前一個 高 2^(1/12) 倍

That factor determines the fret spacing.

這個因素決定品之間的距離

Each fret divides the string's remaining length by 2^(1/12),

每個品都把其餘琴弦的長度 分成 2^(1/12)

making the frequencies increase by half steps.

使頻率隨著每個半音增加

Fretless instruments, like violins,

沒有品的樂器，比如小提琴

make it easier to produce the infinite frequencies between each note,

可以在每個音符之間 有無數個不同的頻率

but add to the challenge of playing intune.

但是很難把握音調

The number of strings and their tuning

琴弦的數量和它們的調音

are custom tailored to the chords we like to play

是造著我們想彈出的和弦

and the physiology of our hands.

和我們的手的結構特製的

Guitar shapes and materials can also vary,

吉他的形狀和材料都不同

and both change the nature and sound of the vibrations.

兩者都可以使振動的性質和聲音改變

Playing two or more strings at the same time

同時撥動兩個或者更多的琴弦

allows you to create new wave patterns like chords and other sound effects.

可以讓你創造新的音波形 如和弦和其他的音效

For example, when you play two notes whose frequencies are close together,

比如，當你同時彈奏兩個 頻率相似的音符時

they add together to create a sound wave whose amplitude rises and falls,

它們共同創造一個 振幅不停起落的聲波

producing a throbbing effect, which guitarists call the beats.

創造一種像脈動一樣的效果 吉他手把這個叫做節拍

And electric guitars give you even more to play with.

電子吉他可以創造的效果更多

The vibrations still start in the strings,

振動從琴弦開始

but then they're translated into electrical signals by pickups

接下來拾音器把它們轉換成電子信號

and transmitted to speakers that create the sound waves.

然後傳送到揚聲器，最後變成聲波

Between the pickups and speakers,

從拾音器到揚聲器

it's possible to process the wave in various ways,

有好多種方式處理聲波

to create effects like distortion, overdrive, wah-wah, delay and flanger.

創造出失真、過速、「娃娃器」 延音、鑲邊等的效果

And lest you think that the physics of music is only useful for entertainment,

如果你覺得音樂中的物理原理 只是為了娛樂而已

consider this.

再仔細想想

Some physicists think that everything in the universe

有些物理學家認為宇宙中的一切事物

is created by the harmonic series of very tiny, very tense strings.

都是由一系列和聲的 「能量弦」組成的

So might our entire reality

難道我們的現實世界

be the extended solo of some cosmic Jimi Hendrix?

只是宇宙版吉米·亨德里克斯 （美國著名歌手）的擴展的獨奏嗎？

Clearly, there's a lot more to strings than meets the ear.

顯然，弦不只有我們所聽到的那麼簡單