Another popular time signature is twelve eight time (+). It tells you there are twelve eighth note beats in each bar. A bar of eighth notes in twelve eight time sounds the same as a bar of triplets in four four time. This is because the twelve individual beats are grouped into threes and counted as four pulses (1 2 3 2 2 3 3 2 3 4 2 3) as demonstrated in the following example.
One of the main reasons for using the twelve eight time signature instead of * is that it becomes easier to count when the eighth notes are subdivided into sixteenth notes. Since there is a number on each eighth note, sixteenth notes can be counted as + (and).
To finish things off, here is a melody which makes use of 16th notes in + time. Notice that each main beat adds up to the equivalent of a dotted quarter note.
A triplet is a group of three evenly spaced notes played within one beat. Eighth note triplets are indicated by three eighth notes grouped together by the numeral 3 and sometimes a bracket or a curved line as well. Eighth note triplets are played with one third of a beat each.
Notice that a bar of eighth note triplets in * time sounds the same as a bar of eighth notes in + time. The difference is that in + time, the eighth note is the basic unit, whereas in + time an eighth note triplet is a quarter note beat divided into three.