Dotted Notes and Triplets

In the previous lesson, every length split in two: the quarter note into two eighth notes, the eighth note into two sixteenth notes. That system covers a lot of what you program, but not everything. Listen to the hi-hat line in this figure, especially at the end of the bar: something speeds up, at a rate that doesn't match any of the lengths you know.

That roll of six notes in a single beat isn't sixteenth notes, which would be four, or thirty-second notes, which would be eight. It's a triplet. Before we study it, let's start with the other exception, which is simpler: the dot.

The dot: one and a half times the length

A small dot placed after a note makes it half again as long. A dotted quarter note is worth a quarter note plus an eighth note, that is, a beat and a half, or six steps on a 1/16 grid. A dotted eighth note is worth an eighth note plus a sixteenth note, three quarters of a beat, or three steps. A dotted half note is worth three beats, or twelve steps. The math is always the same: you take the length and add half of it.

Listen to what this does in a bass line. Two dotted quarter notes, then a quarter note: six steps, six steps, four steps. The bar is filled exactly, but the second note comes in between two beats, on the and of two, and it falls between two kicks, which gives a very recognizable bounce.

This three, three, two split is one of the most widespread rhythms in today's music. You'll hear it in house bass lines, in electronic pop chords, in Afro and Latin percussion, and we'll meet it again in the lesson on drum patterns.

The dot is also used a lot for echo effects. A delay set to a dotted eighth note repeats each note three steps later. Listen to this effect, simulated here with notes: a melody of four very short notes placed on the beats, each followed by its first echo, a dotted eighth later.

You can hear a galloping rhythm appear, even though the melody itself is very simple. Because the echo falls between the notes instead of doubling them, it creates a second rhythm that fills the space. In a delay plugin, this setting is often written 1/8D or “1/8 dotted”. We'll see how to work out these lengths precisely in the lesson on tempo in milliseconds.

The triplet: three in the time of two

A triplet is a group of three even notes that takes up the time normally given to two notes of the same name. Three eighth-note triplets fit in one beat, where there are usually only two eighth notes. Six sixteenth-note triplets fit in one beat, instead of four sixteenth notes. And three quarter-note triplets fit in two beats, instead of two quarter notes.

The best way to understand it is to hear the difference. First, listen to hi-hats in ordinary eighth notes: two per beat, one on the beat and the other on the “and”.

Now the same bar with eighth-note triplets: three hi-hats per beat, perfectly even. To count them, say “one-trip-let, two-trip-let” and so on, with the number landing on the beat.

The motion changes completely: ordinary eighth notes walk, eighth-note triplets roll, almost like a gallop. This is called a compound feel, or a triplet feel, because each beat divides into three instead of two. We'll meet it again in the lesson on odd time signatures, with 12/8.

Software marks triplets with a T: 1/8T for the eighth-note triplet, 1/16T for the sixteenth-note triplet, 1/4T for the quarter-note triplet. Some programs write 1/12 and 1/24 instead, and that makes perfect sense: there are twelve eighth-note triplets in a bar of 4/4, and twenty-four sixteenth-note triplets.

Hi-hat rolls in trap

Let's go back to the first example. In trap, and in a lot of the music that grew out of it, the hi-hats keep switching from one length to another: eighth notes, then sixteenth notes, then a triplet, then sometimes an even faster roll in thirty-second notes. These bursts are often called hi-hat “rolls”. The contrast between straight lengths, which split in two, and triplets, which split in three, makes the hi-hats sound like they're speeding up and putting on the brakes.

Here are two bars built on that principle. In the first, eighth-note triplets slide across the second beat; in the second, a roll of sixteenth-note triplets closes the bar. The kick and the clap stay very simple, with the clap on the third beat, as is common in trap.

Notice that the kick and the clap never leave the ordinary grid. Only the hi-hats play with triplets, and it's precisely that rub between two ways of dividing time that makes the part feel alive.

Setting the grid to triplets

To write a triplet, your grid has to allow it. On an ordinary 1/16 grid, the lines fall on every quarter of a beat, and none of them matches a third of a beat. So switch the grid to triplet mode while you write your roll, then go back to the normal grid for the rest.

You now know all the note lengths. In the next lesson, we'll see what makes a rhythm written with these lengths sound stiff, or on the contrary makes you want to move: offbeats, syncopation and groove.