Compound and irregular meters

▶ Open in Aratu to hear the examples, change them and do the exercises

So far the beat was always a quarter note, and a bar had two, three or four of them. In this lesson the beat changes size: in 6/8 it divides in three, in 7/8 the beats have different lengths, and a triplet can stretch across two beats.

6/8: two beats, each divided in three

A bar of 6/8 has six eighth notes, but a musician does not count to six: they count two beats, each with three eighths, "ONE-two-three, TWO-two-three". Aratu counts the same way. Each word is a beat, a dotted quarter, and ccc is its three eighths:

Try it▶ Hear it in Aratu

meter: 6/8
tempo: 66
hh = ccc ccc
bd = b__ b__
sd = - s

The bass drum plays at the start of each beat and holds through the other two eighths (b__); the snare marks the second beat. Notice that the tempo counts beats, not eighths: tempo: 66 is 66 dotted quarters a minute.

12/8 is the same, with four beats: it is the meter of the slow blues and of many ballads.

Try it▶ Hear it in Aratu

meter: 12/8
tempo: 60
hh = ccc ccc ccc ccc
bd = b__ -   b_b -
sd = -   s   -   s

5/4: five beats

A bar can have five beats, as in "Take Five", the best-known jazz tune in this meter. The rule does not change: five words.

Try it▶ Hear it in Aratu

meter: 5/4
tempo: 160
hh = cc cc cc cc cc
bd = b  -  -  b  -
sd = -  -  s  -  s

7/8: beats of different lengths

In irregular meters, common in Balkan music and in progressive rock, the eighths are grouped into unequal beats. Say how after an =: meter: 7/8 = 2+2+3 is two beats of two eighths and one of three. Count "ONE-two, ONE-two, ONE-two-three".

Each word is a group. A group of two eighths is written cc, a group of three ccc:

Try it▶ Hear it in Aratu

meter: 7/8 = 2+2+3
tempo: 240
hh = cc cc ccc
bd = b_ b_ b__
sd = -  -  -s-

Here the tempo counts eighths: tempo: 240 is 240 eighths a minute. You can also write one word per eighth, seven words, if that is easier to read: hh = c c c c c c c.

Change it to meter: 7/8 = 3+2+2 and adjust the lines: the same bar, with a different swing to it.

Triplets across beats

An eighth-note triplet fits in one beat (ccc). But there is also the quarter-note triplet: three even notes in the space of two beats. A number before the brackets says how many beats the group takes:

Try it▶ Hear it in Aratu

tempo: 80
melody = | 2[c4 d e] f _ | g _ _ _ |
hh = c c c c

Listen to the hi-hat: the three notes of the melody spread over the first two beats, without lining up with the second one. 3[c c c c] is four notes in three beats.

Exercises

A bar of 6/8 with the hi-hat on all six eighths and the bass drum at the start of each beat.

Exercise▶ Hear it in Aratu

meter: 6/8
hh = - -
bd = - -

See an answer

meter: 6/8
hh = ccc ccc
bd = b__ b__

Write a bar of 7/8 grouped 2+2+3, with the hi-hat on every eighth and the bass drum at the start of each group.

Exercise▶ Hear it in Aratu

meter: 7/8 = 2+2+3
hh = - - -
bd = - - -

See an answer

meter: 7/8 = 2+2+3
hh = cc cc ccc
bd = b_ b_ b__

Now 7/8 as 3+2+2: the group of three comes first.

Exercise▶ Hear it in Aratu

meter: 7/8 = 3+2+2
hh = - - -
bd = - - -

See an answer

meter: 7/8 = 3+2+2
hh = ccc cc cc
bd = b__ b_ b_

A quarter-note triplet on the first two beats (C4, D4, E4) and a half note on F4.

Exercise▶ Hear it in Aratu

melody = | c4 d e f |

See an answer

melody = | 2[c4 d e] f _ |