Music Theory for the 21st-Century Classroom

In the present day, the most common time signature is $\begin{array}{c}4\\ 4\end{array}$ (also known as “common time”). It makes sense to introduce durational symbols in the context of $\begin{array}{c}4\\ 4\end{array}$ because a whole note takes up a whole measure in $\begin{array}{c}4\\ 4\end{array}$, a half note takes up half a measure of $\begin{array}{c}4\\ 4\end{array}$, a quarter note takes up $\frac{1}{4}$ of a measure, and so on.

Here are durational symbols for rests.

To put this information into practice, listen to the durational values double in speed in each measure of the following example.

Two rare durational values are the double whole note (also called a “breve”) and the 64th note, which is twice as fast as a 32nd note.