Bars and time signatures
Bar lines divide music into bars. The time signature at the start, such as 3/4 or 4/4, tells you how many beats fit in each bar, and every bar must be exactly full.
Why
Why do you count "one, two, three" for a waltz and "one, two" for a march?
Not all beats are equally strong. In a waltz you feel one heavy beat and two light ones: turn, step, step. In a march there are two: left, right.
Those groups of beats are called bars. On paper we draw a line between them, so you can see where the heavy beat falls.
See it and hear it
Choose a time signature and fill the bar with notes and rests. The counter tells you how many beats still fit. A note that is too long will not fit.
0 of 4 beats
Description of the picture
An empty bar on a rhythm line with a time signature at the start. Buttons add a semibreve, minim, crotchet or quaver, or their rests. A counter shows, for example, 3 of 4 beats. A full bar gets a tick.
Get it
A bar line is a vertical line through the stave. Between two bar lines is one bar. The first beat of every bar is the heaviest.
The time signature sits at the start as two numbers, one above the other. The top number tells you how many beats are in a bar. The bottom number tells you which note is one beat: 4 means a crotchet, 8 a quaver.
In 2/4 there is room for 2 crotchets, in 3/4 for 3 and in 4/4 for 4. In 6/8 there is room for 6 quavers: that is as much as 3 crotchets, but you feel them in two groups of three.
Every bar must be exactly full: all the notes and rests together add up to the number of beats in the time signature, no more and no less.
Top number: how many beats per bar. Bottom number: 4 = crotchet, 8 = quaver. All the notes and rests in a bar together = the number of beats.
Worked example
A bar in 3/4 already has a crotchet and a crotchet rest. What still needs to go in?
A bar in 3/4 has 3 beats.
3
There are already 1+
1= 2 beats. 3−
2= 1 - Answer
1 more beat is needed: a crotchet or a crotchet rest.
Do it
Choose a level. You get a new exercise every time, checked straight away.
Pitfalls
Wrong: 3/4 is a fraction: three quarters of something.
A time signature looks like a fraction, but you read it as two agreements: how many beats, and which note is one beat.
Right: 3/4: three beats per bar, each beat a crotchet. That is also why there is no fraction line.
Wrong: 6/8 is the same as 3/4, because both have 3 crotchets per bar.
They are the same length, but you group them differently: 3/4 feels like three beats, 6/8 like two groups of three quavers.
Right: 3/4: one, two, three. 6/8: one-two-three, four-five-six.
Wrong: If a note no longer fits in the bar, you put it in anyway.
Then the bar no longer adds up and everyone's pulse gets muddled.
Right: Split the note across the bar line and join the two parts with a little curve (a tie).
In real life
- A waltz, such as The Blue Danube by Johann Strauss, is in 3/4: one heavy beat and two light ones.
- Almost all pop and rock is in 4/4. The drummer often hits the bass drum on beats 1 and 3.
- A march played by the brass band, or the music for a parade, is often in 2/4: one, two, left, right.
History
Old manuscripts often have no bar lines. Only in the 17th century did bar lines become the usual way to divide music into bars.
At the table
Pick a song together and conduct along: do you count to two, three or four in each bar? On which beat does your hand go down?
A question to talk about together, for parents and children. There is no wrong answer.