Triplets in Music: Three in the Time of Two

What is a triplet in music?

A triplet is a group of three equal notes that fills the space of two notes of the same written value. It is marked with a small 3 above or below the group, often with a bracket when the notes are not beamed together.

Triplets divide a beat into three in a meter that normally divides it into two. In 4/4 a quarter-note beat splits into two eighth notes; an eighth-note triplet splits the same beat into three. The triplet is the most common tuplet, the general name for any group that divides a span into an irregular number of parts.

How long does a triplet note last?

Multiply the plain note value by 2/3. Three triplet notes replace two plain notes, so each triplet note lasts two-thirds of its plain counterpart.

triplet note (ms) = plain note (ms) × 2 ÷ 3

• Eighth-note triplet — three in one quarter-note beat; each lasts ⅓ beat.
• Quarter-note triplet — three in two beats (one half note); each lasts ⅔ beat.
• Sixteenth-note triplet — three in one eighth note, six in one beat; each lasts ⅙ beat.
• Half-note triplet — three in four beats (one whole note); each lasts 1⅓ beats.

Worked example at 100 BPM: the quarter note is 60,000 ÷ 100 = 600 ms, the plain eighth is 300 ms, and the eighth-note triplet is 300 × 2 ÷ 3 = 200 ms. Three of them add back up to one 600 ms beat.

Triplet lengths at 100, 120 and 140 BPM

At 120 BPM an eighth-note triplet lasts 166.67 ms, a quarter-note triplet 333.33 ms and a sixteenth-note triplet 83.33 ms. The table compares each triplet with the plain value it replaces.

Triplet values are common delay settings because the repeats fall off the straight grid and add a rolling feel. The triplet delay calculator lists straight, dotted and triplet times side by side, and the guide to note values gives the plain lengths for every symbol.

Other tuplets: duplets, quintuplets and sextuplets

A tuplet fits any number of notes into a span that normally holds a different number. The number written over the group states how many notes it contains.

The duplet is the mirror image of the triplet: it brings a two-part division into a compound meter, where the beat normally splits into three. Each duplet note lasts 1.5 eighth notes, the same length as a dotted eighth. The dotted note guide covers that equivalence.

How is swing different from triplets?

Swing is a performance style; a triplet is an exact written division. Swung eighth notes are usually written as plain eighths and played long-short, with the first note longer than the second.

The triplet gives swing its common reference point. Playing the first two notes of an eighth-note triplet tied together, then the third, produces a 2 : 1 long-short pair. At 120 BPM that pair lasts 333.33 ms plus 166.67 ms. Many jazz charts state this with a heading such as “Swing” or a pair of eighths set equal to a triplet quarter and eighth.

Real swing does not lock to that ratio. Players vary the long-short proportion by style and tempo, and at fast tempos swung eighths move closer to even eighths. The 2 : 1 triplet value is a notation convention and a DAW setting, not a measurement of how every musician swings.

Music that runs on continuous triplets is often written in 12/8 instead. A 12/8 bar at ♩. = 120 holds twelve eighth notes of 166.67 ms each, identical to four beats of eighth-note triplets in 4/4 at 120 BPM. The 12/8 time signature guide shows how to count it.

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