Notes, Duration & Time Signatures
We’ve looked at how the time signatures determine how many of what kind of note fills a measure. But, songs are made up from many different kinds of notes. Here, we’ll look at how those different kinds of notes are still controlled by time signatures.
In our first time signature example, we showed 3/4 time and showed that it takes 3 quarter notes to fill a bar. You can see that example again, below.
But, what if your song uses many kinds of notes? How much time would a whole note get? Or an eighth note? The time signature still tells us how many of each kind, although a bit of math is needed to make sense of it. For instance, 3 quarter notes are needed to fill a bar in 3/4 time. So, how many eighths?
In the example below, the second bar shows eighth notes. If 3 quarter notes fill a bar, it takes 6 eighth notes. An eighth note is half of a quarter note in duration because an eighth is half of a quarter. In the third bar, we show a whole note. From our discussion of notes you should remember that a whole note fills a measure. In this case, the whole note is equal to 3 quarter notes.
The math works the same for any time signature. A whole note fills a bar. A half note is half the duration of a whole note. A quarter note is half of that again, and so on.
In the example below, the first bar is filled with a whole note. In 4/4 time, a whole note is equal to 4 quarter notes, because 4 quarter notes is what it takes to fill a measure. Half notes are twice the size of quarter notes. You need only two of them to fill a bar, and you can see that in the second measure. You can see the 4 quater notes in the 3rd measure, and in the 4th bar we show eighth notes. An eighth note is half the duration of a quarter note, so how many eighth notes to fill a bar in 4/4 time?
Time signatures tell us how many (top number) of what kind of note (bottom number) it takes to fill a measure. When using notes other than the kind shown in the bottom number, it is simple math that tells us how many of each kind we might need.
Next, as our exploration of music theory continues, we’ll start looking at scales.