
I don’t know the origin of the 8-count, so I can’t give you a historical perspective. Sets of 8 are better for predicting where the music is going, whether you’re a dancer or just a person who enjoys listening to music.” They’re better for identifying the structure in popular music, which you need for choreographing movement, a moot point to a musician.

I write about music and dance and to quote from my book, Hear the Beat, Feel the Music: Count, Clap and Tap Your Way to Remarkable Rhythm ( ): “Sets of 8 are a dancer thing.

If you listen closely, an 8-count will sound like a "sentence" of music, which makes it an easier structure to work with when choreographing dance. In a lot of 4/4 time music, two 4-beat measures will be rhythmically paired, which is what creates the 8-count. The two systems are different but related and can coexist (although some musicians have never heard of the 8-count so they might argue that point).

In the 4/4 time signature, which may be over 95% of popular music today, dancers count beats in "sets of 8" also known as the "8-count" or the "dancer's 8." Musicians count in measures of 4 beats.
