Simple vs Compound Meter: The Difference, the 6-9-12 Rule and How to Count Each

You read 6/8 at the start of a piece, count six eighth notes like a slow 3/4 waltz, and the rhythm sounds wrong. The difference between simple vs compound meter is the reason: compound meter groups those eighths in threes, so the bar swings in two big beats. Once you see how each beat divides, you can count any time signature on sight.

This guide gives you the one rule, a 3x2 grid of every common meter, the counting syllables, and a tap exercise you can run with a metronome today.

What is the difference between simple and compound meter?

Simple meter divides each beat into two equal parts, and compound meter divides each beat into three. Wikipedia's article on metre in music states it in those terms: in simple time each beat "divides naturally into two", in compound time "into three equal parts".

That one difference changes how the beat is written. A beat that splits in two can be a plain note, such as a quarter note that holds two eighths. A beat that splits in three needs a dotted note, because a dotted quarter holds exactly three eighths.

The beat is the pulse you tap your foot to. If you need a refresher on how the note values relate, see note values in music.

Duple, triple and quadruple: the second question

Every meter answers two questions, and the second is how many beats sit in one bar. Two beats make duple meter, three make triple and four make quadruple.

Put the two questions together and you get six families. Simple duple, simple triple and simple quadruple split their beats in two.

Compound duple, compound triple and compound quadruple split their beats in three. Every common time signature fits one of the six boxes in the grid above.

How to tell simple from compound meter, step by step

The time signature tells you the meter in five quick checks. Run them in order the first few times, and soon you will read the answer at a glance.

1. Read the top number. A 2, 3 or 4 on top means simple meter. A 6, 9 or 12 on top means compound meter, as Wikipedia's time signature article defines it.
2. Find the beats per bar. In simple meter the top number is the beat count. In compound meter divide the top number by 3: 6/8 has 2 beats, 9/8 has 3 and 12/8 has 4.
3. Name the beat note. In simple meter the bottom number is the beat: 4 means a quarter note, 2 a half note. In compound meter join three of the bottom-number notes into one dotted note, so three eighths make a dotted quarter.
4. Check the beaming. Printed music beams notes by the beat. In 6/8 the eighths come in groups of three; in 3/4 they come in pairs.
5. Say the count out loud. Count one number per beat and fill the divisions with syllables. If the syllables come in pairs, the meter is simple; if they come in threes, it is compound.

Free toolMetronomePractise with a steady beat

The part people get wrong: the top number is not the beat count

The top number of a compound signature counts divisions, not beats. Lesson 4b of the open textbook Inquiry-Based Music Theory puts it plainly: in compound meter the top number tells you how many divisions are in the bar, and the bottom number gives the value of one division.

So 6/8 means six eighth-note divisions, grouped into two dotted-quarter beats. Count 6/8 as "1 2 3 4 5 6" at a moderate tempo and you are playing it as a fast six-beat bar, which is not how the music moves.

Simple vs compound meter: the 3x2 grid

The grid below lists every common time signature with its beat note and the way the beat divides. Read across a row to compare a simple meter with its compound partner.

Each compound meter is its simple partner with every beat split in three. 6/8 is 2/4 with three-way beats, 9/8 matches 3/4, and 12/8 matches 4/4. The choice between the last pair is a real arranging decision, covered in choosing between 4/4 and 12/8.

Pairs that share a bar length: 3/4 and 6/8, 3/2 and 6/4

Some simple and compound meters fill a bar with the same total length, and these pairs cause most of the confusion. A bar of 3/4 and a bar of 6/8 both hold six eighth notes, but 3/4 groups them 2+2+2 into three quarter-note beats, while 6/8 groups them 3+3 into two dotted-quarter beats.

Wikipedia's metre article notes that because the bars are the same length, music can "slip" between the two feels. Bernstein's "America" from West Side Story is its example of a song that exploits the switch. For a closer look at this one pair, read how 6/8 is different from 3/4, and for the beaming rules see beaming rhythms in 3/8 and 6/8.

The same pairing holds one size up. 3/2 holds six quarter notes as three half-note beats, and 6/4 holds six quarter notes as two dotted-half beats.

That is why 3/2 is simple triple, not compound: its top number is 3, and each half-note beat divides in two. The case for writing in 3/2 is in why 3/2 might fit your composition.

How to count and feel each meter

Counting syllables make the division audible. You say a number on every beat and a syllable on every division, so the pattern of syllables tells you the meter.

In simple meter you count "1-& 2-&", and Wikipedia's article on counting in music adds "e" and "a" for sixteenths: "1-e-&-a". In compound meter you count "1-la-li 2-la-li", or "1-&-a 2-&-a"; the same article lists both "One-la-lee" and "One-and-ah" for 6/8. Pick one system and keep it, so a three-way division never sounds like a sixteenth-note count.

Feel follows the count. Compound duple has a lilting, rocking motion of two long beats, which is why jigs and barcarolles sit in 6/8. Simple triple has three even beats with the weight on beat 1, which is the waltz.

Listening examples you can check

Listening is the fastest way to feel the difference, but only with pieces whose meter is documented. The examples below come from the Wikipedia time signature table and the Inquiry-Based Music Theory lesson.

• Compound duple (6/8): Mozart, String Quartet No. 17 in B-flat major, K. 458 "The Hunt", first movement.
• Compound triple (9/8): Debussy, "Clair de lune"; Wagner, "The Ride of the Valkyries".
• Compound quadruple (12/8): Beethoven, Symphony No. 6 "Pastoral", second movement, "Scene by the Brook".

Play one of them and tap your foot on the slow beat. Then whisper "la-li" between the taps; if the syllables fit without rushing, you are feeling the compound beat.

How to check your feel with a metronome

A metronome tells you which pulse you are following. Set it to click only the beat, tap every division yourself, and you will hear at once whether your grouping matches the meter.

Run the two rows below at the same eighth-note speed. In 6/8, set the metronome to 60 clicks per minute and treat each click as a dotted quarter, so you tap three eighths per click.

In 3/4, set it to 90 and treat each click as a quarter, so you tap two eighths per click. Both rows move at 180 eighth notes per minute; only the place of the click changes.

The metronome with subdivisions can add quiet triplet divisions under each click, which turns it into a compound-meter guide. To find the tempo of a recording before you play along, tap it into the BPM counter.

A workable five-minute test

Five signals tell you whether your feel holds after each session:

• Click alignment: Does your loudest tap land on the click in every bar, for two full minutes?
• Syllable fit: Can you say "1-la-li 2-la-li" against the 6/8 click with no pause before the next number?
• Switching: Can you change from the 6/8 row to the 3/4 row every four bars without stopping?
• Reading: Can you name the meter and beat note of ten signatures in the rhythm exercises without a mistake?
• Tempo range: Can you hold the 6/8 feel with the click at 50 and at 80?

Common mistakes with compound meter

Most errors come from treating the top number as the beat count. Watch for these.

• Counting 6/8 in six: At a normal tempo it makes the music plod. Count two beats, each with "la-li".
• Grouping 6/8 as 2+2+2: That turns it into 3/4. Group the eighths 3+3, as the beams show.
• Calling 3/2 compound: The bar has six quarter notes, but a 3 on top always means simple triple. Three half-note beats, each split in two.
• Using one syllable set for both: "1-&-a" in 6/8 and "1-e-&-a" in 4/4 sound alike in a hurry. Use "la-li" for compound if you mix them up.
• Hearing triplets as compound meter: A triplet inside 4/4 borrows a three-way split for one beat. The meter is still simple, because the other beats split in two.
• Ignoring tempo: The written meter stays the same, but the felt beat can change. See the edge case below.

Edge case: very slow 6/8 and very fast 3/8

Tempo can move the beat you feel without changing the meter. Wikipedia's metre article notes that conductors usually beat 6/8 in two, but at a very slow tempo all six eighths may be marked.

The opposite also happens. A fast 3/8 or 3/4 is often felt with one beat per bar, and the three divisions then sound like a compound beat. In both cases the time signature still names the written meter; the tempo only decides which level you tap.

Your simple vs compound meter checklist

• Top number 2, 3 or 4: simple meter; the top number is the beat count.
• Top number 6, 9 or 12: compound meter; divide by 3 for the beats per bar.
• Beat note: plain note in simple meter, dotted note in compound meter.
• Beaming: pairs point to simple meter, groups of three point to compound meter.
• Count: "1-&" for simple, "1-la-li" for compound.
• Practice: five minutes of the tap exercise, with the click on the beat only.

Practice turns the rule into a reflex. ChordIQ has a Rhythm Trainer where you read a written rhythm and tap it in time across complexity levels 1 to 10, plus Rhythm: Echo, where you hear a rhythm and tap it back. With Pro, Custom Rhythm Practice lets you pick the rhythm cells, tempo and meter, and a one-time latency calibration keeps your device's audio delay from counting as your error.

For practice at the instrument, the Piano Companion metronome runs from 30 to 250 BPM with 1 to 12 beats per bar and a visual and audible beat. PRO adds subdivisions, polyrhythms from 2 to 9 and saved presets.