3/4 vs 6/8: hear the same six notes in different groups
Six evenly spaced notes can form three beats or two. Hear the difference in two short original recordings, then keep the notes steady while changing their grouping.
Six notes can make two different patterns
A bar of 3/4 can contain six eighth notes. A bar of 6/8 can contain six eighth notes too. The useful difference is how they form beats: three groups of two in 3/4, or two groups of three in the usual 6/8 feel.
Try the two original recordings below. Every note has the same pitch and starts at the same time in both versions. Only the pattern of louder and quieter notes changes. You need no instrument or music-reading skills.
First listen: follow the larger beats
Start at a comfortable low volume. Each recording plays four bars, with a short silence before and after. The strongest sound marks the beginning of each six-note bar. The other accented sounds are a little quieter than that first sound, but louder than their neighbours.
Play A, then B. Lightly tap a finger on each accented sound, including the first one. Between the strongest sounds, do your taps form three beats or two? If you prefer to work without audio, use the complete numbered map after the question.
Recording A
Transcript
No speech. Silence from 0 to 0.4 seconds. From 0.4 to 9.9 seconds, 24 short synthesized tones of the same pitch, with a new tone every 0.4 seconds. Four six-note groups start at 0.4, 2.8, 5.2 and 7.6 seconds. In each group, the first tone is loudest; the third and fifth are moderately accented, and the second, fourth and sixth are quieter. The grouping is three pairs: 1–2, 3–4, 5–6. Each tone fades before the next. The last tone ends at 9.9 seconds; silence continues to the end at 10.8 seconds.
Recording B
Transcript
No speech. Silence from 0 to 0.4 seconds. From 0.4 to 9.9 seconds, 24 short synthesized tones of the same pitch, with a new tone every 0.4 seconds. Four six-note groups start at 0.4, 2.8, 5.2 and 7.6 seconds. In each group, the first tone is loudest; the fourth is moderately accented, and the second, third, fifth and sixth are quieter. The grouping is two threes: 1–2–3, 4–5–6. Each tone fades before the next. The last tone ends at 9.9 seconds; silence continues to the end at 10.8 seconds.
Which recording has two main beats?
Listen for the moderately accented notes as well as the strongest first note. Choose an answer, or open the answer explanations below. The numbered map later gives the same task without sound.
Answers and explanations
- A: A accents positions 1, 3 and 5: three groups of two. Each group begins a quarter-note beat.
- B: B accents positions 1 and 4: two groups of three. Each group begins a dotted-quarter-note beat.
- Both: each has six notes: Both have six notes per bar, but note count alone does not tell you how those notes are grouped into beats.
Read the groups without sound
The numbers below identify the six successive note positions; they are not pitch names. Each pair of brackets is one main beat. All six notes sound in both recordings. The first note of the bar is strongest; the first note of every other bracket receives a smaller accent.
One bar, six equal note slots
Positions 1 2 3 4 5 6
A: 3/4 [1 2] [3 4] [5 6]
B: 6/8 [1 2 3] [4 5 6]Each bracket begins on a beat. In A the beat starts are 1, 3 and 5; in B they are 1 and 4.
Why the signatures are different
In 3/4, a bar has three quarter-note beats. Each quarter note divides into two eighth notes. That makes three pairs: 2 + 2 + 2. This is called simple triple meter: three beats, each dividing into two.
In the usual compound-duple reading of 6/8, a bar has two dotted-quarter-note beats. A dotted quarter lasts as long as three eighth notes. That makes two threes: 3 + 3. The 6 counts the eighth-note divisions in the bar, rather than six main beats.
Open Music Theory and the University of Massachusetts teaching chapter explain this distinction between the main beat and its divisions. The three eighth notes within a 6/8 beat are ordinary divisions of that beat; they do not need a triplet marking.
Keep the note spacing; change the beat
In these recordings, successive eighth-note positions are 0.4 seconds apart. A six-note bar therefore lasts 2.4 seconds in either version. In A, the main beats are 0.8 seconds apart; in B, they are 1.2 seconds apart. Keeping eighth notes equally fast does not keep the main-beat rate the same.
This is a deliberately clear accent exercise. In actual music, every main beat need not be louder than its neighbours, and the tempo or phrasing can affect which pulse a listener follows. These recordings demonstrate the usual grouping; they are not a rule for diagnosing every performance by counting loud notes.
Try changing the grouping yourself
Speak six evenly spaced syllables and repeat without an extra pause at the end. For A, say “ONE and TWO and THREE and”, with a small emphasis on the numbers and a little more on ONE. Keep the syllables equally spaced.
For B, use “ONE la li TWO la li”. Here “la li” simply fills the two smaller divisions after each number. Keep the same spacing between syllables as before: do not squeeze three syllables into the time previously used for two.
Alternate two bars of A with two bars of B. There are still six syllables in every bar. What changes is where the next main beat arrives: after two syllables or after three. For a silent version, point along six equally spaced marks and circle them first in pairs, then in threes.
One final check
Suppose you remove every accent and play six identical notes at equal intervals, repeating them without another cue. Could the notes alone tell you whether the intended grouping is 3/4 or 6/8?
No. Our distinguishing clue was the grouping. Once that clue is removed, the same six evenly spaced notes can fit either map. A score, surrounding music or another part could supply the missing information.