📚 Year 7 WJEC Music: Formula & Theorem Quick Reference | Year 7 WJEC 音乐：公式定理速查手册
This handbook gathers the essential 'formulas' and 'theorems' of music theory that every Year 7 WJEC student needs to know. From note lengths to scale patterns and chord building, these rules form the backbone of composing, performing and listening work. Use this guide to revise the facts, test yourself on the terminology and always keep the musical mathematics close at hand.
这本手册汇集了每位 Year 7 WJEC 学生都需要掌握的音乐理论核心“公式”与“定理”。从音符时值到音阶样式、再到和弦的构建，这些规则是作曲、表演与听力学习的基础。请使用本指南复习要点、自测术语，并时刻牢记音乐中的这些“数学关系”。
1. Note Values and Rest Durations | 音符时值与休止符长度
The duration of a sound or silence in music is measured in beats. Every note value has an equivalent rest that lasts for the same number of beats. The relationships are based on simple fractions: each symbol length is half the value of the next longer symbol.
声音或休止在音乐中的时长以拍子为单位度量。每个音符时值都有一个与之对应的、保持相同拍数的休止符。这些关系基于简单的分数关系：每一个符号的时长是下一个更长符号时值的一半。
| English Name | 中文名称 | Note Symbol | Rest Symbol | Beats (4/4) |
|---|---|---|---|---|
| Semibreve | 全音符 | 𝅗𝅥 | 𝄻 | 4 |
| Minim | 二分音符 | 𝅗𝅥 | 𝄼 | 2 |
| Crotchet | 四分音符 | 𝅘𝅥 | 𝄽 | 1 |
| Quaver | 八分音符 | 𝅘𝅥𝅮 | 𝄾 | ½ |
| Semiquaver | 十六分音符 | 𝅘𝅥𝅯 | 𝄿 | ¼ |
Dotted notes add half the original value again; a dotted minim lasts for 3 beats (2 + 1).
需要记住的基本公式：两个十六分音符等于一个八分音符，两个八分音符等于一个四分音符，两个四分音符等于一个二分音符，两个二分音符等于一个全音符。附点音符增加原有时值的一半；例如附点二分音符持续3拍（2 + 1）。
2. Time Signatures and Metre | 拍号与节拍
A time signature is written at the start of a piece and tells you how many beats are in each bar and what type of note equals one beat. The top number shows the count of beats per bar; the bottom number shows the note value that receives one beat (4 stands for a crotchet, 8 for a quaver).
拍号记写在乐曲的开头，告诉你每小节有几拍，以及哪种音符为一拍。上方数字表示每小节拍数；下方数字表示以何种音符为一拍（4 代表四分音符，8 代表八分音符）。
The most common time signature in Year 7 is 4/4, also called common time. It means four crotchet beats per bar. Other regular metres include 2/4 (two crotchet beats) and 3/4 (three crotchet beats, used in waltzes).
Year 7 中最常见的拍号是 4/4，也叫普通拍子。它意味着每小节有四拍，以四分音符为一拍。其他常见的规则拍子包括 2/4（每小节两拍，以四分音符为一拍）和 3/4（每小节三拍，以四分音符为一拍，常用于圆舞曲）。
3. The Stave, Clefs and Pitch Names | 五线谱、谱号与音名
Music is written on a stave made up of five lines and four spaces. Notes are placed on lines and spaces to indicate pitch. The higher the position, the higher the pitch.
音乐记写在由五条线和四个间组成的五线谱上。音符可以记在线上或间里以表示音高。位置越高，音高越高。
A clef assigns a specific pitch to one of the lines, allowing us to name all the other lines and spaces. The treble clef (𝄞) is a G clef: it curls around the second line, fixing it as G above middle C. The bass clef (𝄢) is an F clef: its two dots sit either side of the fourth line, marking it as F below middle C.
谱号将某一特定音高赋予五线谱上的某一条线，从而可以推算出所有其他线与间的音名。高音谱号（𝄞）是 G 谱号：它环绕第二线，将该线定为中央 C 上方的 G。低音谱号（𝄢）是 F 谱号：两个点分别位于第四线的两侧，将该线定为中央 C 下方的 F。
In the treble clef, the lines from bottom to top are E, G, B, D, F (Every Good Boy Deserves Football). The spaces spell F A C E. In the bass clef, the lines are G, B, D, F, A (Great Big Dogs Fight Alpacas) and the spaces are A, C, E, G (All Cows Eat Grass).
在高音谱表中，五条线由下至上依次为 E, G, B, D, F（可用“Every Good Boy Deserves Football”来记忆），四个间里的音名依次为 F, A, C, E。在低音谱表中，五条线为 G, B, D, F, A（Great Big Dogs Fight Alpacas），间里的音为 A, C, E, G（All Cows Eat Grass）。
4. Accidentals: Sharps, Flats and Naturals | 临时记号：升号、降号与还原号
Accidentals are symbols that alter the pitch of a note by a semitone. A sharp (♯) raises the pitch by one semitone; a flat (♭) lowers the pitch by one semitone; a natural (♮) cancels any previous sharp or flat, returning the note to its original pitch.
临时记号是用来将一个音升高或降低半音的符号。升号（♯）将音升高半音；降号（♭）将音降低半音；还原号（♮）取消之前所有的升号或降号，将音恢复至其原始音高。
Accidentals can appear in front of individual notes within a bar (they last until the end of that bar) or at the beginning of the stave as a key signature, where they apply to every octave of that note throughout the piece unless cancelled.
临时记号可以出现在一小节内的个别音符前（其效果持续至该小节结束），也可以作为调号出现在谱表的开头，此时它将在全曲中对所有八度的同名音生效，除非被临时记号的还原号抵消。
5. Major Scale Formula | 大调音阶公式
All major scales follow the same pattern of tones (T) and semitones (S). A tone equals two semitones. The formula is: T, T, S, T, T, T, S.
所有大调音阶都遵循相同的全音（T）与半音（S）排列模式。一个全音等于两个半音。音阶公式为：全、全、半、全、全、全、半。
Starting on any note and applying this sequence will produce a major scale. For C major, the notes are C, D, E, F, G, A, B, C – the semitones fall between E–F and B–C, which are natural semitones.
从任意一个音开始，按此序列排列，就能得到一个大调音阶。以 C 大调为例，其各音为 C, D, E, F, G, A, B, C——其中半音位于 E–F 和 B–C 之间，这两个都是自然半音。
For G major, you need to raise the seventh note by a semitone to fit the pattern: G, A, B, C, D, E, F♯, G. The semitone step occurs between F♯ and G.
对于 G 大调，你需要将第七级音升高半音才能符合公式：G, A, B, C, D, E, F♯, G。半音出现在 F♯ 和 G 之间。
6. Intervals: Semitones and Tones | 音程：半音与全音
An interval is the distance in pitch between two notes. The smallest interval used in Western music is the semitone (one fret on a guitar, one adjacent key on a piano). A tone is equal to two semitones.
音程是两个音之间的音高距离。西方音乐中最小的音程是半音（吉他上一个品格的距离，钢琴上相邻琴键的距离）。一个全音等于两个半音。
Intervals are named by combining a number (distance in letter names) and a quality. Key intervals to learn by ear and formula:
音程的名称由级数（音名涵盖的数量）和性质组合而成。需要靠耳朵分辨并用公式计算的关键音程有：
| Interval (English/中文) | Semitones | Example |
|---|---|---|
| Perfect Unison 纯一度 | 0 | C to C |
| Major 2nd 大二度 | 2 | C to D |
| Major 3rd 大三度 | 4 | C to E |
| Perfect 4th 纯四度 | 5 | C to F |
| Perfect 5th 纯五度 | 7 | C to G |
| Major 6th 大六度 | 9 | C to A |
| Major 7th 大七度 | 11 | C to B |
| Octave 八度 | 12 | C to C' |
When the higher interval is reduced by a semitone (always keeping the letter name the same), it becomes minor, diminished or perfect as appropriate. In Year 7, focus on recognising the perfect 5th and the major 3rd by ear.
当较高的音降低半音（保持音名不变）时，音程的性质会变成小音程、减音程或纯音程等。在 Year 7 阶段，请重点练习用耳朵辨认纯五度和大三度。
7. Dynamics | 力度标记
Dynamics tell musicians how loudly or softly to play. They are written as abbreviations from Italian terms and are often placed beneath the stave. A sudden change or a gradual change in volume adds shape and emotion to a performance.
力度标记告诉表演者应该以何等强度演奏。它们通常以意大利语缩写形式记写在五线谱下方。力度的突然变化或逐渐变化可以为演奏赋予轮廓和情感。
| Symbol | Italian Term | 中文含义 |
|---|---|---|
| pp | pianissimo | 非常弱 |
| p | piano | 弱 |
| mp | mezzo-piano | 中弱 |
| mf | mezzo-forte | 中强 |
| f | forte | 强 |
| ff | fortissimo | 非常强 |
| cresc. (or hairpin <) | crescendo | 渐强 |
| dim. (or hairpin >) | diminuendo | 渐弱 |
8. Tempo Markings | 速度标记
The speed of a piece of music is called its tempo. Tempo words are traditionally written in Italian at the top of the score and can be supplemented with a metronome mark showing beats per minute (BPM).
音乐作品的速度称为 tempo。速度术语通常使用意大利语记写在乐谱开头，并可以辅以表示每分钟拍数（BPM）的节拍器标记。
| Italian Term | 中文含义 | Typical BPM |
|---|---|---|
| Largo | 广板（缓慢） | 40-60 |
| Adagio | 柔板（慢速） | 66-76 |
| Andante | 行板（步行速度） | 76-108 |
| Moderato | 中板 | 108-120 |
| Allegro | 快板（快速活泼） | 120-168 |
| Presto | 急板（非常快） | 168-200 |
9. Triad Construction | 三和弦构建
A triad is a three-note chord built by stacking two thirds on top of a root note. The quality of a triad depends on the number of semitones between each note. This is one of the most important 'chord formulas' for Year 7 compositions.
三和弦是由三个音组成的和弦，通过在根音上方叠加两个三度音程形成。三和弦的性质取决于各音之间的半音数量。这是 Year 7 作曲中最重要的“和弦公式”之一。
Major Triad Formula: Root + 4 semitones + 3 semitones
大调和弦公式：根音 + 4 个半音 + 3 个半音
Minor Triad Formula: Root + 3 semitones + 4 semitones
