Lesson 10: 三連音(Triplets)

In addition to the different note values introduced in Lesson 5 and Lesson 6, there is a special class of notes that occurs frequently in both classical music and contemporary music, called the triplets (三連音). As the name suggests, it is used when you want to divide a duration into 3 equal subdivisions in any simple time signature.

Triplets are used whenever you want to divide any duration into 3 equal parts in a simple time signature, because in any simple time signature, the beats can only be divided into 2, 4,... equal subdivisions (power of 2, basically).

In a simple time signature, usually two quarter notes equal to one half note; and three triplet quarter notes equal to one half note (two normal quarter notes). Similarly, three triplet eighth notes would be equal to one quarter note (i.e. two normal eighth notes). Triplets are usually written with a number '3' above or below the notes. Sometimes, you will see a square bracket or a slur across the triplet, and sometimes only the number is seen. Rests and dotted notes can be used as needed in triplets. This is one of the common ways to write triplets:


Triplets can also be considered the building blocks of compound time signatures, because all beats in compound time signatures are divided into 3 equal subdivisions. E.g. in the common time signature (4/4), if all four beats are written as triplets, it will be equivalent to the compound key signature 12/8. Since all beats in compound time signature are triplets, they will not be labeled as triplets, and therefore, a beat in a compound time signature is a dotted quarter note, instead of a quarter note.

Optional:
There may be circumstances where we want to divide one beat (a dotted note) in a compound time signature into 2 equal subdivisions. To achieve that, a duplet is used. Two duplet eighth notes equal one dotted quarter note (i.e. 3 compound eighth notes). Theoretically, one beat can be divided into n equal subdivisions, by the use of tuplets (the general term for notes like duplets and triplets).

Lesson 9: 拍號 (Time Signatures)

Time signatures typically consist of 2 numbers like in a fraction. It is always written after the key signature at the beginning of a piece, and will not be written again unless the time signature changes halfway in the piece (see Lesson 8). There are 3 types of time signatures: simple, compound, and complex. Each type of time signatures will be disccused below.

The two numbers in a simple time signature tell you the following information:

• Top number: how many beats there are in a bar/measure.
• Bottom number: what the value of one beat is, or the beat value.

E.g. Consider the time signature . The bottom number is 4, which means that each beat is a quarter note; the top number is 2, which means that there are 2 quarter notes in each measure. Similarly, the time signature means that there are 3 beats in each measure, and each beat is an eighth note. An important concept in simple time signature is that each beat can be divided into two subdivisions.



The most commonly used simple time signature is . Because it is so commonly used, it is sometimes written as 'C', which denotes 'the common time'.

In the second type of time signatures: compound time signatures, the numbers are read a little differently.

• Top number: how many subdivisions there are in a bar/measure.
• Bottom number: what the value/duration of one subdivision is.

So what is 'one beat' in a compound time signature? In compound time signatures, each beat is divided into three subdivisions (instead of 2 in simple time signatures). In other words, 'one beat' would be 3 times of a subdivided note in a compound time signature. This also implies that in all compound time signatures, the top number should be divisible by 3 (except for cases like 3/4 or 3/8, because technically it is pointless to have only 1 beat per measure). This is how you can distinguish between simple and compound time signatures.

E.g. The time signature means that each subdivision is an eighth note (bottom number), and there are 6 subdivisions in each measure, meaning there are 6/3 = 2 beats per measure. One beat in this time signature would be a dotted quarter note, because it is 3 times of an eighth note. Similarly, the time signature means there are now 9 subdivisions per measure, which means there are 9/3 = 3 beats per measure. Note that in all compound time signatures, 'a beat' will always be a dotted note.

The third type of time signatures, complex time signatures, are a lot less encountered than simple and compound time signatures. It typically involves a prime number (other than 2 and 3) on the top. E.g. 5/4 or 7/4. In these complex time signatures, a measure can be interpreted differently according to the composer. E.g. for the case of 5/4, the 5 beats can be played as 3+2 or 2+3, and in the case of 7/4, a measure can be divided into 4+3 or 2+3+2, etc.

Things to learn in this lesson:

1. What do the numbers in a time signature stand for?
2. Be able to differentiate between simple, compound, and complex time signatures.
3. What are the differences between simple and compound time signatures?

Lesson 8: 如何讀譜 (Reading piano scores)

The few most important things that you will need to pay attention to when playing songs/pieces are those illustrated in the following diagram:

• Clefs: Most worship songs that you will encounter will have treble clef on top and bass clef at the bottom. However, in classical music, it is not uncommon to have either all treble clefs or all bass clefs for both hands, so it is always good to check.
• Key signature: This tells you what key the song is in. The key signature is shown on all the staffs throughout the piece. The key of a song can change in the middle of it, so it is important to pay attention to such changes.
• Time signature: This tells you how many beats are there in each measure (or bar). However, this is completely unrelated to the tempo (speed) of the piece. A more extensive explanation on how to read time signature will be covered in later lessons.
• Bar lines: A bar line is drawn to separate measures. E.g. each bar has 4 beats in a given song, then a bar line will be drawn every 4 beats.

In addition to the components mentioned above, there are also other components that define the song/piece. For example,

• the tempo of the piece is typically written at the beginning of a piece, above the 1st line.
• the dynamics (relative loudness) of the piece can be written anywhere in the piece and changes as the piece goes.
• there are also a wide variation of words used in music to mark the mood in the piece.