An eighth note triplet is a group of three evenly spaced notes played within one beat. Eighth note triplets are indicated by three eighth notes with the number 3 written either above or below the group. Sometimes the triplet has a bracket or a curved line around the number 3. The notes are played with a third of a beat each.
Here are some 7th chords played with a triplet rhythm.
Triplets sound great when combined with the notes of the Blues scale. Listen to the following example and then make up some of your own triplet based riffs from the Blues scale.