Beats, measures and time signatures

Just like we use a clock to measure the speed of a process or to divide our time into hours, minutes and seconds, we similarly have devices or methods, whatever you would like to say, to measure music.To measure music with respect to time we have some terms that need to be defined first.

BEAT: This is a regular pulse that can be heard or implied or felt. Just like heartbeat.

TEMPO: This is the speed of the pulse.

MEASURE/BAR: The space between two bar lines.

METER: This is the time signature. It tells how many beats are there in each measure.

RHYTHM: All of the above things combined together give the rhythm of the music. So you can vary the rhythm just by varying any of the above.

Now how to read time signatures or meters? You must have come across things like 4/4 or 3/4 or 6/8 etc.  Let us first define note values/duration.

Now how much time is equivalent to one beat? If the time signature is 4/4, then the quarter note ( the denominator) gets one beat equivalent time. If it is 3/8, then one beat will be measured by an eighth note and so on.

Time signature tells you how the music is to be counted. The time signature is written at the beginning of the staff after the clef and key signature.

Time signatures consist of two numbers written like a fraction. The top number tells you how many beats to count and the bottom number will tell you what kind of note to count ( quarter notes , eighth notes etc).

Let us take the example of the common time signature 4/4. This means count 4 (the top number) quarter notes (the bottom number) to each bar or measure. So the rhythm feel or the pulse count is like 1-2-3-4, 1-2-3-4, 1-2-3-4 and so on. Now the time signature 4/4 implies that all the notes in a bar must add up to 4 quarter notes. You can use sixteenth notes, eighth notes whatever you want, but the total sum should be 4 quarter notes. For example you can use 8 eighth notes or 4 eighth notes and 2 quarter notes etc. Because in each case you will be taking time equal to 4 quarter notes.

There is special symbol for some common time signatures. The 4/4 is called the common time and a C (this is not actually a C, it is a half circle) is written in place of 4/4. Another is the 2/2 which is also called cut time. It is represented by a C with a slash through it.