Motifs, Repetition and Variation

Think of the melodies that stay in your head after a night out or a drive. They rarely have many different notes. On the other hand, almost all of them repeat a small idea, over and over, with just enough change that you don't get tired of it. That's the mechanism we're going to take apart here, because it can be learned and it works in every genre.

An idea that wanders, an idea that comes back

Let's start by comparing two two-bar melodies over the same loop, Am then F. The first one repeats nothing: every group of notes is new. It still stays in the scale and puts chord tones on the strong beats, as we learned in the previous lesson. Listen to it.

Now listen to the second one. It uses only a tiny three-note idea, which it repeats and barely changes.

The second version has fewer ideas, and that's exactly why it sticks. After two listens, you could sing it; the first one, probably not. A melody the ear can anticipate a little is pleasing, because the ear feels it understands it.

The motif, a short cell

A motif is a small musical idea, often two to six notes long, that you recognize when it comes back. It has two ingredients: a rhythm and a contour. The rhythm is actually the sturdier of the two. If you keep a motif's rhythm and change all its notes, people still recognize it; if you keep the notes and shake up the rhythm, much less so.

To find a motif, there's no need to look for a whole melody. Hum three or four notes over your loop, tap a rhythm on the table, or start from the chord tones in an order you like. A good motif is short and simple. All the interesting work comes afterward, when you bring it to life.

Repeat, then vary

Repetition establishes the motif, and variation keeps it from getting old. Between the two there's a balance you adjust by ear, but a few techniques come up again and again, in every style.

• Vary the rhythm. You keep the notes and change where they fall or how long they last: the motif can start an offbeat later, or stretch its last note.
• Change one note. You keep the rhythm and almost all the notes, and alter one of them, often to fit the new chord.
• Change the ending. The start of the motif stays the same, and only its conclusion changes direction or landing note.
• Move the motif. You replay the same shape starting from another note of the scale, higher or lower. This shifted repetition is called a sequence.

Listen to these techniques applied to a single motif, over the loop Am, F, C, G. The starting motif goes down: three quick notes, then a long one.

The line keeps its identity from start to finish, even though no two bars are quite the same. Your ear follows the rhythm, which doesn't move, and that makes it all the more willing to accept the note changes. Over F, the first E becomes F so it lands on a chord tone. Over C, the whole shape moves up: that's a sequence. Over G, the start is shifted again, but the ending rises instead of falling, which leaves the phrase open before the loop comes back around.

Question and answer

Another very old technique is to have two phrases talk to each other. The first asks a question: it ends on a note that leaves things hanging, often the second or fifth degree of the scale. The second answers: it starts like the first, then wraps things up, usually on the tonic. These are called question and answer phrases, or antecedent and consequent in theory books.

The question makes you want to hear what comes next, and the answer brings rest. The pair works because the two phrases resemble each other: the answer is a variation of the question, with a different ending. So here you find, on a larger scale, the technique of changing the end of a motif.

Two bars, plus two bars

This way of dividing things up gives you a practical method that suits electronic music well, where almost everything is counted in fours and eights of bars. First, write a two-bar idea. Follow it with two bars that answer it: the same idea with a different ending, or a contrasting idea. You get a four-bar phrase, the length of a classic chord loop.

To get to eight bars, apply the same principle one level up. Here are two very common plans.

In the first plan, the four-bar phrase comes back, and its second ending closes more clearly than the first. In the second, the idea is heard twice, then it evolves before the conclusion. Either way, the listener first hears something familiar, then something new at the right moment.

The hook, the idea people remember

In a track, the strongest motif often becomes the hook: the little phrase that grabs the ear and comes back at the key moment, in the chorus or the drop. There's nothing magic about a hook. It's a short motif with a recognizable rhythm, repeated enough to settle in and varied enough not to get old. It can be sung, played by a lead, or fit into a chopped vocal sample.

Three questions help you judge whether you've got a hook. Can you sing it after two listens? Does it fit in two bars or less? Is its rhythm recognizable when you tap it on a table, without the notes? If you answer yes to all three, you have an idea that deserves to be put up front in the arrangement.

So far, we've stayed up top, in the melody. The next lesson goes all the way down, to bass lines.