The Oxford Dictionary of Music defines a triplet as a ‘group of 3 notes… …written where a group of 2 notes is suggested by time-siganture’.
In other words, a triplet is when three notes are played in the time of two.
There are some exceptions to this rule which will be covered towards the end of this lesson.
As discussed in the definition, triplets are groups of three notes:
As you can see, they are identified as triplets by a ‘3’ above or below the three notes, depending on the direction of the stems.
As triplets are three notes in the time of two, the three quaver triplets here last as long as two quavers.
Here is the quaver triplets sounded at the same time as crotchets, and then quavers so you can better hear how the quaver triplets fit into one crotchet beat (or two quaver beats).
You can also have triplet notes with semiquavers, which would be notated in the same way as quaver.
Alternatively, you can have triplet notes with crotchets/quarter notes, minims/half notes, or any other note.
Crotchet/quarter triplet notes look like this:
Here, there are lines drawn above or below the notes with a 3 in between them.
Triplet Notes with altered rhythms
You can also have triplets with dots or tied notes:
Here, although the notes are of different lengths, combined they are still triplets equal to one minim beat (or two crotchet notes).
It is important to not think of the three notes as always being of the same value.
Instead, if their combined value is equal to two notes (in the above instance two crotchet notes), they can be a triplet.
Following this rule, you can also have two notes in a triplet:
Again, due to these two notes being triplets, they are instead also equal to two crotchet notes (or one minim).
Therefore, triplets allow rhythms which are otherwise impossible to create.
They are uncommon in music, but are certainly not rare and you will come across them time and again within your musical career.
As a side note, triplets are not needed to be known until grade 3 for those doing trinity exams, however they are good to be introduced now even if you are doing trinity’s syllabus.