Compound and Asymmetric Time Signatures
Senior 3 · Music
Compound and Asymmetric Time Signatures
Lesson 2 of 4
20 min
Beethoven wrote the little piano piece known as Für Elise in 1810. Pianists all over the world learn its opening, and almost all of them notice the time signature: a 3 above an 8. Every time signature you used in S1 had a 4 or a 2 at the bottom. Here the beat is a quaver.
Count the anacrusis and each bar in quavers: the two opening semiquavers make one quaver; each full bar holds exactly three quavers' worth of notes and rests.
Definition
Time signature: the two numbers at the start of the music. The top number gives the number of beats in a bar. The bottom number gives the note value of one beat: 2 = minim, 4 = crotchet, 8 = quaver.
Two-eight time: two quaver beats in each bar (simple duple time).
Three-eight time: three quaver beats in each bar (simple triple time).
When the beat is a quaver, every note is measured in quavers instead of crotchets. The notes have not changed; only the unit you count in has.
| Note or rest | Beats in two-four or three-four (crotchet beat) | Beats in two-eight or three-eight (quaver beat) |
|---|---|---|
| Dotted crotchet | 3 (a whole bar of three-eight) | |
| Crotchet | 1 | 2 (a whole bar of two-eight) |
| Quaver | 1 | |
| Semiquaver |
A minim cannot fit in a bar of two-eight or three-eight: it lasts 4 quavers. A whole bar of silence, however, is always written with a semibreve rest, whatever the time signature. In three-eight it simply means "rest for this whole bar".
Two-eight has the same pattern of strong and weak beats as two-four (strong, weak), but each bar is half as long on paper. Quavers are beamed in pairs, one beam per bar:
Three-eight is a simple triple time: three quaver beats, each of which can be split into two semiquavers. At a slow tempo you count and conduct it "1 2 3", like three-four. At a quick tempo, such as a waltz-like dance or the opening of Für Elise played at speed, the three quavers go by too fast to beat separately. You then feel one beat in each bar, a dotted crotchet split into three quavers. That "one big beat divided into three" is the doorway to compound time in the next lesson.
Worked example
Worked example 1: rewriting three-four in three-eight. A bar of three-four reads: minim, crotchet. Rewrite it in three-eight so it sounds the same at a matching tempo.
Step 1. Three-eight uses a quaver beat instead of a crotchet beat, so every note value is halved.
Step 2. Minim becomes crotchet; crotchet becomes quaver.
Answer: crotchet, quaver. Check: 2 + 1 = 3 quaver beats.
Worked example
Worked example 2: is this bar of three-eight complete? The bar holds a quaver, a semiquaver rest and three semiquavers (the second bar of Für Elise).
Step 1. Measure in quavers: quaver = 1, semiquaver rest = , three semiquavers = .
Step 2. Total: .
Answer: yes, three quaver beats.
When a choir or band reads two-eight or three-eight, the leader beats time with these patterns. Practise them while you sing the rhythms of this lesson.
Video: "The Difference Between 3/4 and 3/8 Time Signatures", Music Matters. Listen for how the same three-beat pattern feels slower or quicker depending on which note carries the beat. American names: quarter note = crotchet, eighth note = quaver.
Tip
Read the bottom number as a note. 4 = crotchet, 8 = quaver. "Three-eight" then reads as "three quavers in every bar", and you can check any bar by adding its quavers.
Warning
Common mistake: putting a minim or a dotted minim in three-eight because "three-eight is like three-four". The bar is only three quavers long; the longest single note that fits is a dotted crotchet.
Practice
Remember
Sources and credits
