In music, time is measured differently from how we usually do – in seconds, minutes, hours. It is connected to how slow or fast musicians play when performing a song or piece.
When we talk about ‘time’ in music we’re referring to a number of things, and the most immediate is its rhythm or pace; for example, we say that a particular song has a slow or a fast rhythm. This is called ‘tempo’, an Italian word meaning… time!
The instrument that sets up the tempo in music is called a ‘METRONOME’. It marks the bpm or the beats per minute. If we set the metronome at 80 bpm, it means that in one minute there will be 80 beats; if we set it at 72 bpm, there will be 72 beats per minute.
Let’s do a practical test. Set the metronome at 72 bpm and get ready with a stopwatch, Synchronize with the speed of the bpm and start the stopwatch by starting to count the number of beats. After one minute you should have counted 72 beats.
If we set it at 60 bpm, beats will overlap with seconds: 60 bpm means 60 beats in a minute, so one single beat of the metronome coincides with 1 second.
There is a relation between tempo, musical time and time as we normally mean it (seconds, minutes, hours), but it is just a coincidence.
However, this connection actually grows closer when we think about the duration of a musical piece.
When, for example, we say that a song lasts 2 minutes and 30, seconds we are referring to our time as we commonly measure it. But that song is following its own tempo (bpm).
Meanwhile, let’s specify what the MUSICAL UNIT of time is: the quarter note. It’s indicated with a fractional value: 1/4. One beat is equal to 1\4.
So, if you happen to see a musical score, you will notice that at it has a ‘4/4’ at the beginning.
4\4 time is the most common and widespread. Several songs or musical pieces are written in 4\4. We can say that it is a natural time.
4\4 should be read like this: the denominator refers to the unit of measurement, the numerator refers to the number of beats that fit in a bar.