When we watch a film or a play, we know that the actors probably learned their lines from a script,
看电影或戏剧时，我们知道演员大概是看剧本知道台词，
which essentially tells them what to say and when to say it.
剧本基本上告诉演员说什么和何时说。
A piece of written music operates on exactly the same principle.
一段乐谱和剧本的作用完全相同。
In a very basic sense, it tells a performer what to play and when to play it.
很基本地讲，乐谱告诉演奏者演奏什么和什么时候演奏。
Aesthetically speaking, there's a world of difference between, say, Beethoven and Justin Bieber,
从美学的角度来讲，比方说，贝多芬和贾斯汀·比伯完全不同，
but both artists have used the same building blocks to create their music: notes.
但两位创作者都用了同样的基本构架来创作音乐：音符。
And although the end result can sound quite complicated, the logic behind musical notes is actually pretty straightforward.
尽管结果会听起来相当复杂，但音符背后的逻辑实际上是非常简单的。
Let's take a look at the foundational elements to music notation and how they interact to create a work of art.
让我们来看一下音乐符号的基本元素，以及它们是如何互动来创作音乐作品的。
Music is written on five parallel lines that go across the page.
音符写在五条平行线上，横贯整页。
These five lines are called a staff, and a staff operates on two axes: up and down and left to right.
这五条线叫五线谱，五线谱在两个轴之间：上下和左右。
The up-and-down axis tells the performer the pitch of the note or what note to play,
上下轴告诉演奏者音调或弹哪那个音符，
and the left-to-right axis tells the performer the rhythm of the note or when to play it.
左右轴告诉演奏者音符的节奏或何时弹。
Let's start with pitch. To help us out, we're going to use a piano,
让我们从音调开始。为帮我们搞清楚，我们打算用钢琴来说明，
but this system works for pretty much any instrument you can think of.
但这个系统对差不多你能想到的任何乐器都适用。
In the Western music tradition, pitches are named after the first seven letters of the alphabet, A, B, C, D, E, F, and G.
根据西方的音乐传统，音调是按前七个字母来命名的。A，B，C，D，E，F和G。
After that, the cycle repeats itself: A, B, C, D, E, F, G, A, B, C, D, E, F, G, and so on.
此后，循环下去：A，B，C，D，E，F，G。A，B，C，D，E，F，G。以此类推。
But how do these pitches get their names?
但这些音调是怎样取名的呢？
Well, for example, if you played an F and then played another F higher or lower on the piano,
举例来说，如果你弹F，再弹另一个F，只是高低音不同，
you'd notice that they sound pretty similar compared to, say, a B.
其实听起来差不多，跟B相比就不同了。
Going back to the staff, every line and every space between two lines represents a separate pitch.
再回到五线谱。每条线，还有线与线间的空格都代表一个音调。
If we put a note on one of these lines or one of these spaces, we're telling a performer to play that pitch.
如果我们在其中的一条线上或空格里放上一个音符，演奏者就知道要弹什么音调。
The higher up on the staff a note is placed, the higher the pitch.
五线谱上音符越高，表示音调越高。
But there are obviously many, many more pitches than the nine that these lines and spaces gives us.
但音乐有数之不尽的音调，远不止这几条线和空格带给我们的几个音。
A grand piano, for example, can play 88 separate notes.
例如，三角钢琴可以弹88个不同的音。
So how do we condense 88 notes onto a single staff?
因此我们怎么样把这88个音符压缩到五线谱上呢？
We use something called a clef, a weird-looking figure placed at the beginning of the staff,
我们用一个叫谱号的东西。谱号的样子看起来怪怪的，放在五线谱的开始，
which acts like a reference point, telling you that a particular line or space corresponds to a specific note on your instrument.
作用类似于一个参考点，告诉你某条线或空格对应你乐器上的某个音符。
If we want to play notes that aren't on the staff,
如果我们想弹不在五线谱上的音符，
we kind of cheat and draw extra little lines called ledger lines and place the notes on them.
这就有点像作弊，额外多划了一些线，这叫做加线，把加的音符写在了上面。

If we have to draw so many ledger lines that it gets confusing, then we need to change to a different clef.
如果我们非得画这么多加线，导致线混乱了，我们需要换成不同的谱号。
As for telling a performer when to play the notes, two main elements control this: the beat and the rhythm.
至于让演奏者何时弹这些音符，由两个要素控制这一点：节拍和节奏。
The beat of a piece of music is, by itself, kind of boring. It sounds like this.
一首曲子的节拍有点单调无聊，听起来像这样。
Notice that it doesn't change, it just plugs along quite happily.
注意节拍不变，只是相当快乐地前进着。
It can go slow or fast or whatever you like, really.
可以放慢也可以加快，随便你怎么变化。
The point is that just like the second hand on a clock divides one minute into sixty seconds,
节拍就像时钟的秒针，将一分钟分为60秒，
with each second just as long as every other second,
每一秒长度都一样。
the beat divides a piece of music into little fragments of time that are all the same length: beats.
节拍将一首曲子分成很多个小段落，每一段长度相同，就是节拍。
With a steady beat as a foundation, we can add rhythm to our pitches, and that's when music really starts to happen.
以一个稳定的节拍为基础，我们可以开始把节奏加到音调上，那才是音乐真正开始。
This is a quarter note. It's the most basic unit of rhythm, and it's worth one beat.
这是个四分音符。它是最基本的节奏单位，为一拍。
This is a half note, and it's worth two beats.
这是个半分音符，为两拍。
This whole note here is worth four beats, and these little guys are eighth notes, worth half a beat each.
这个全音符为四拍，这些小家伙是八分音符，每一个为半拍。
"Great," you say, "what does that mean?"
“好极了”，你说，“那是什么意思？”
You might have noticed that across the length of a staff, there are little lines dividing it into small sections.
你应该有注意到五线谱上有几条小线将乐谱分成几个小段落。
These are bar lines and we refer to each section as a bar.
这些是小节线，我们把每一部分作为一个小节。
At the beginning of a piece of music, just after the clef, is something called the time signature,
乐谱之初，就在谱号之后，是叫做拍号的东西，
which tells a performer how many beats are in each bar.
它告诉演奏者每一小节有几拍。
This says there are two beats in each bar, this says there are three, this one four, and so on.
这个拍号表示一小节有两拍，这是三拍，四拍，以此类推。
The bottom number tells us what kind of note is to be used as the basic unit for the beat.
下面的数字告诉我们要用什么音符当作一拍。
One corresponds to a whole note, two to a half note, four to a quarter note, and eight to an eighth note, and so on.
一是全音符，二是二分音符，四是四分音符，八是八分音符，以此类推。
So this time signature here tells us that there are four quarter notes in each bar,
乐谱上的拍号告诉演奏者一小节有四拍，
one, two, three, four; one, two, three, four, and so on.
1，2，3，4；1，2，3，4，以此类推。
But like I said before, if we just stick to the beat, it gets kind of boring,
但就像之前说的，如果我们只按这个节拍，有点儿令人乏味，
so we'll replace some quarter notes with different rhythms.
所以我们用一些不同节奏的四分音符来代替。
Notice that even though the number of notes in each bar has changed, the total number of beats in each bar hasn't.
注意尽管每小节的音符数量已改变，但每小节的节拍总数没变。
So, what does our musical creation sound like?
因此我们的音乐创作听上去怎么样？
Eh, sounds okay, but maybe a bit thin, right?
听上去还可以，但可能有点单调，是吧？
Let's add another instrument with its own pitch and rhythm. Now it's sounding like music.
让我们加上另一种有它自己的音调和节奏的乐器。现在它听上去像音乐了。
Sure, it takes some practice to get used to reading it quickly and playing what we see on our instrument,
当然，习惯于快速读谱、在乐器上演奏我们看到的东西，这是需要一些练习的，
but, with a bit of time and patience, you could be the next Beethoven or Justin Bieber.
但只要花点时间跟耐心，你就有可能是下一个贝多芬或者贾斯汀·比伯。