What is a Bar ?
A Bar ( or Measure ) is the next unit of time in music after a "beat" .
It is the arrangement of beats into patterns by introducing accents into the underlying pulse created by the beats.
The arrangement of these accents determine the length of a Bar i.e. if the accent comes round every 4 beats then the bars will be 4 beats in length ( 4/4 bars ) - if the accent comes every 5 beats then the bars would be 5 beats long ( 5/4 bars ) - if the accent comes every 6 beats then the bars would be 6 beats long ( 6/4 bars )etc.
The top number in a Time Signature [ see the tab below - the numbers in front of each bar are time signatures ] tells you how many beats are in each bar.
In written music the bars are denoted by upright lines ( the Bar Lines ) in the example below there are 4 bars each with a different time signature denoting different lengths of bar.
Most music is in 4/4 time ( also known as Common Time ) so
I suggest you stick to that for the moment. Once you have a good grasp of
4/4 time other time signatures are easier to understand.
Don't confuse Rhythm with Time - within the 4/4 time structure an almost infinite variety of rhythms are possible.
Leave rhythm out of the equation for the moment and try playing chords or notes with an accent ( a louder hit on beat one ) every 4 beats — 1 -2-3-4 — 1 -2-3-4 etc.
You will then be playing 4/4 Bars - this is called playing Straight Time
Practice counting everything you do in fours - e.g. walking around you could count your footsteps. Also when listening to music try to spot the bar lines.