In music, any melody is simple to learn. And that’s because a “melody” is really just a pattern of notes that sound good together—as they’re played one after another. For example, the song “Twinkle, Twinkle, Little Star” is simply a C major scale that’s been chopped up and rearranged into a nice, little tune.

This melody is easy to follow and it’s easy to play. But if you look closely, you’ll also see that something is missing. I mean, how are we supposed to know how long each note should last? If music notation was doing its job, it would show us both the pitch AND the duration of each note.

Just like pitch, duration is an important part of any song. And that’s because music needs time to move forward and do its thing. Without time, music would be nothing. So as we play each note—moving from left to right—we also need to know how long the notes should last. Which is how we can give a song its sense of flow and direction.

Of course, our melody of “Twinkle, Twinkle, Little Star” already gives us a couple of clues about duration. And we can use those to see how time works in music. For example, we can easily see that the song has been divided into clean, little segments. And these segments—which are called “measures” (or “bars”)—help us keep track of when to play each note. To keep things simple, each measure has only a few notes … and that means we can move through the melody in bite-size pieces.

With measures, it’s easy to see how this melody moves forward at a nice, steady pace. Like the tick of a clock, all the notes form a regular pattern as they follow one after another. In fact, if you tap your foot along with the notes, you’ll hear what’s called the “beat” of the song. Like the beat of a heart, it keeps on repeating to give life and movement to the melody.

Like most songs, this melody has four beats in each measure. Which we can hear if we play though this same pattern again. Starting at the “top” (or beginning), let’s count the beats as we hit each note. We’ll start by counting 1 … 2 … 3 … 4 in the first measure. And then repeat the same pattern of beats like this:

It’s pretty easy, really. We simply repeat the same pattern of beats in each measure. But did you notice anything special during that last pass through the melody? If you didn’t, then look again … a couple of notes actually lasted for two beats instead of just one. (The first is at the end of measure two and the other is at the end of measure four.) Instead of getting just a single beat like all the other notes, these notes (with the lyrics “star” and “are”) lasted for a slightly longer amount of time.

So how do we show that these notes have a different duration? We simply use a few special symbols that musicians designed for this very purpose….