The two numbers at the start of a piece of music look simple, yet they cause more counting mistakes than almost anything else on the page. Once you understand the difference between simple, compound and odd meters, most of that confusion disappears, and setting up a metronome for any time signature becomes straightforward.
What the two numbers mean
The top number tells you how many units are in each bar (also called a measure). The bottom number tells you which note value is the unit:
- 2 = half note
- 4 = quarter note
- 8 = eighth note
- 16 = sixteenth note
So 3/4 means three quarter notes per bar, and 6/8 means six eighth notes per bar. That definition is exact, but it does not tell you where the felt beats are. For that, you need to know which family the meter belongs to.
Simple meters: the beat divides into two
In a simple meter, each beat naturally splits into two equal halves. The top number is usually 2, 3 or 4, and you count the beats directly.
- 2/4: two quarter-note beats, counted "1 & 2 &." Marches and polkas.
- 3/4: three quarter-note beats, counted "1 & 2 & 3 &." Waltzes, minuets and many hymns.
- 4/4: four quarter-note beats, counted "1 & 2 & 3 & 4 &." Also called common time and written as a large C. Most pop, rock, hip-hop, country and jazz.
- 2/2: two half-note beats, known as cut time or alla breve and written as a C with a vertical line through it. It holds the same notes as 4/4 but is felt in two.
Compound meters: the beat divides into three
In a compound meter, each felt beat is a dotted note that divides into three. The top number is 6, 9 or 12, and you divide it by three to find the number of felt beats.
- 6/8: two dotted-quarter beats, each holding three eighths, counted "1 la li 2 la li." Irish jigs, barcarolles and many slow rock ballads.
- 9/8: three dotted-quarter beats, counted "1 la li 2 la li 3 la li." The slip jig is a classic example.
- 12/8: four dotted-quarter beats, counted "1 la li 2 la li 3 la li 4 la li." Slow blues, gospel and 1950s doo-wop ballads.
The key insight is that 6/8 is not a fast version of 3/4. Both contain six eighth notes, but they group them differently: 3/4 groups them into three pairs (1 & 2 & 3 &), while 6/8 groups them into two sets of three (1 la li 2 la li). Composers sometimes switch between the two feels on purpose, a device called hemiola, which you will hear at cadences in Baroque dance movements and throughout many Latin American styles.
Odd meters: groups of twos and threes
Meters such as 5/4, 7/8 and 11/8 cannot be divided into equal beats. Musicians handle them by breaking the bar into groups of two and three. The grouping is part of the music, so the same time signature can feel very different depending on how it is grouped.
- 5/4: usually grouped 3+2 or 2+3. Dave Brubeck's "Take Five" and Holst's "Mars, the Bringer of War" are well-known pieces in 5/4.
- 7/8: grouped 2+2+3, 3+2+2 or 2+3+2. Common in Balkan folk dance music.
- 9/8 as an odd meter: 9/8 is not always compound. Brubeck's "Blue Rondo à la Turk" groups its nine eighths as 2+2+2+3, which feels completely different from a slip jig's 3+3+3.
The diagram below shows a bar of 7/8 grouped two ways. The accented eighth notes mark the start of each group: count "1 2 1 2 1 2 3" for 2+2+3 and "1 2 3 1 2 1 2" for 3+2+2.
The total length of the bar is identical in both versions. Only the position of the accents changes, yet 2+2+3 feels as if it stretches at the end, while 3+2+2 starts long and then tightens up.
Time signatures at a glance
| Time signature | Type | Felt beats per bar | Count | Metronome setup |
|---|---|---|---|---|
| 2/4 | Simple duple | 2 | 1 & 2 & | 2 beats, quarter-note click, accent on 1 |
| 3/4 | Simple triple | 3 | 1 & 2 & 3 & | 3 beats, accent on 1 |
| 4/4 | Simple quadruple | 4 | 1 & 2 & 3 & 4 & | 4 beats, accent on 1 (or click on 2 and 4) |
| 2/2 | Simple duple | 2 | 1 & 2 & (in half notes) | 2 beats, half-note click at half the quarter-note tempo |
| 6/8 | Compound duple | 2 | 1 la li 2 la li | 6 eighths accented on 1 and 4, or 2 beats with triplets |
| 9/8 | Compound triple | 3 | 1 la li 2 la li 3 la li | 9 eighths accented on 1, 4 and 7, or 3 beats with triplets |
| 12/8 | Compound quadruple | 4 | 1 la li 2 la li 3 la li 4 la li | 4 beats with triplets, or 12 eighths accented on 1, 4, 7 and 10 |
| 5/4 | Odd | 5, grouped 3+2 or 2+3 | 1 2 3 4 5 | 5 beats, accents on 1 and 4 (3+2) or on 1 and 3 (2+3) |
| 7/8 | Odd | 3 uneven groups | 1 2 1 2 1 2 3 | 7 eighths with a 2+2+3 (or other) accent grouping |
How to set your metronome for each type
Simple meters
Set the top number as the beat count and click on the quarter note, or on the half note for 2/2. Keep beat 1 accented so you always know where the bar starts. In cut time, a piece you would count at ♩ = 200 in four becomes a half-note click at 100 BPM in two, which is much easier to follow and closer to how the music should feel.
Compound meters
You have two good options, and it is worth practicing both:
- Click every eighth note. Set 6, 9 or 12 beats with an eighth-note value and accent the first eighth of every group of three. This is precise and excellent for learning rhythms, but the clicks get busy at faster tempos: a 6/8 piece at 100 dotted-quarter beats per minute means 300 eighths per minute, the very top of the metronome's range.
- Click the dotted quarter. Set 2, 3 or 4 beats and turn on triplet subdivision. You now hear the felt beat strongly and the eighths quietly. This is how most experienced players think of compound time once the rhythms are learned.
Converting between the two is simple: the eighth-note BPM equals the dotted-quarter BPM multiplied by three.
Odd meters
Set the number of beats to the top number (7 for 7/8) with an eighth-note value, then choose an accent grouping such as 2+2+3. You can also build any grouping by hand by clicking the beat dots: make beat 1 strong and set the first beat of every other group to accent. Start slowly. Around 140 eighth notes per minute is a comfortable learning tempo for 7/8, and counting the groups aloud ("1 2, 1 2, 1 2 3") before you play makes a big difference.
A five-minute counting drill
- Pick one time signature and set the metronome with accents on each group.
- Count aloud for 4 bars, emphasizing the start of each group.
- Clap only the accented beats for 4 bars while still counting under your breath.
- Clap every eighth (or every beat) for 4 bars, making the accented claps louder.
- Mute the click for 4 bars using silent bars and keep going. When the click returns, you should land together on beat 1.
Repeat with a different grouping of the same meter, 2+2+3 and then 3+2+2, and notice how the same number of notes produces a different groove. This is the quickest way to make odd meters feel natural instead of mathematical. To go deeper into how beats split into smaller units, read our guide to subdivisions and swing.
Common mistakes
- Counting 6/8 in six at every tempo. Slow 6/8 can be counted in six, but once the tempo picks up, feel it in two or it will sound plodding.
- Treating 2/2 like a fast 4/4. The notes are the same, but the beat is the half note. Accenting every quarter makes cut time sound heavy.
- Ignoring the written grouping in odd meters. The beaming in the score (how eighth notes are joined together) usually shows the intended grouping. Follow it.
- Losing the downbeat after a long note. Keep a strong accent on beat 1 until the meter feels automatic.
Ready to try one? Pick a time signature and run the counting drill above with the click.