“What’s the difference between 3/4 time and 6/8 time?”

There are many parallels between music and math but there are some differences, too. In math, 3/4 and 6/8 are the same; in music, they are not. Recently one of our clinic participants asked about the difference. We admit that it can be confusing, so here are some thoughts.

Six-eight time means that each measure of music consists of six beats, each of which is an eighth note. Three-four time means that each measure consists of three beats, each of which is a quarter note. Since six eighth notes last for the same amount of time as three quarter notes, why are the two time signatures different?

The difference is in how the eighth notes are GROUPED. In 6/8 time, the eighth notes are grouped into two sets of three beats; the accent usually falls on the first and fourth eighth note of the measure. In 3/4 time, the eighth notes are grouped into three sets of two, meaning that the accents fall on the first, third and fifth eight notes of the measure.

Three-four time is used in waltzes, both from the classical era such as “Blue Danube” and from the jazz repertoire, including “Someday My Prince Will Come.” Three-four is also associated with energetic sing-along songs such as “Oom-Pah-Pah” from “Oliver” and “Take Me Out to the Ball Game.” Other popular tunes in three-four time include “Happy Birthday”, “Star Spangled Banner”, “First Noel” and “We Wish You A Merry Christmas.”

Six-eight is sometimes considered a “duple” meter because the measure is broken down into two distinct halves. Many marches, such as John Philip Sousa’s “Liberty Bell” and “76 Trombones” from “The Music Man” use 6/8. It’s also common in Irish tunes, both traditional fiddle melodies such as the “Swallowtail Jig” and Celtic rock songs like the Dropkick Murphys’ “I’m Shipping Up to Boston”. Notice how in these examples, there is a strong emphasis on two beats per measure, but each beat can be subdivided into three (“ONE” and a “TWO” and a; or “ONE two three FOUR five six.”)

Sometimes, the line between 3/4 and 6/8 can be blurred. Dr. Anthony Fesmire’s composition “Dance” (heard on our “Reclaimed” CD) starts in 6/8 time but shifts to 3/4 time. In this performance from our recent clinic, the shift to 3/4 occurs at 1:10; the return to 6/8 happens at 1:47. The shift happens later as well – watch the complete performance of “Dance” here and see if you can figure out where!