# How long is a bar? [closed]

i have knowledge in reading tonic solfa notation. 4/4, 6/8 etc. I also have knowledge in music and audio production with the use of computer softwares, e.g FL Studios. I wish to know about the length of a bar. And also, about meaaures. thank you...

The length of a bar isn't measured, musically, in any units like inches or millimetres! And really, musically, not measured in time units like seconds etc.

A bar is a convenient way to split up a tune. Most tunes have a rhythm running through them, which is repetitive. A pattern. We count through, and establish when the pattern repeats. Then we know how a bar must be represented.

Often, we count 1 2 3 4 1 2 3 4. So that song is said to be 'in 4'. We then need to decide how to subdivide that bar, and often it's into 4 crotchets. That gives us the bottom number. a little like fraction - 4/4.

If the count is 1 2 3 1 2 3 then it could be 3/4.

Now to the question - and answer. The speed, or tempo is dictated by how slowly or quickly we had to count 1 2 3 4 etc. These days, it's noted as b.p.m., which is beats per minute. So, at 60 bpm for those 4 crotchets in a bar, one bar will last 4 seconds. At 120bpm, it'll be 2 secs. What we don't do is use a stopwatch to time a bar - unless we're writing for cartoons, films, and so on!

For example, if the time signature was `4/4` then the bar would be 4 crotchets (quarter notes) long. However, if the time signature was `6/8` then the bar would be 6 quavers (eighth notes) long.
The duration of the bar (in terms of time), is given by the bpm, such that the time of a bar is `60 * number of beats in a bar / bpm` in seconds. E.g. `100 bpm` in `4/4` would be `2.4` seconds per bar.