A stable body is a still body.* In order to move, our bodies must be destabilized. One way of understanding dance is that it is fundamentally controlled falling, and of course, we can only fall when our balance is destabilized.
Can music help destabilize?
Music which alternately emphasizes the pulse and has syncopation (notes or emphases which fall between pulses or beats), destabilizes the pulse and propels the moving body.
Consider the ubiquitous “long long short” rhythmic pattern. It’s present in many musics throughout the world, and is half of a 3-2 clave. Try clapping it and you’ll recognize it.
The Xs are claps and the -s are rests:
||: X - - X - - X - | X - - X - - X - :||
Try counting out loud while clapping:
||: "1 2 3 1 2 3 1 2" | "1 2 3 1 2 3 1 2":||
Why is this rhythm so common in dance music? I think it's because it has a perfect balance of stability, destabilization, and propulsion to inspire movement. Let's take a tour through one cycle of this rhythm, with a little analysis:
STABILITY: The first note is fully stable and grounded. It is the big “home” beat of each cycle.
DESTABILIZATION: The second note is an upbeat, it's syncopated, unstable, and has the most potential energy, which is released and drops us from the furthest height on our way back to landing on the stable downbeat of the next cycle. The syncopated second note causes an undulation in the body, around the beat. I feel like it has an "up-ness" and movement "bounces off" this note.
PROPULSION: Headed back toward stability, the third note, a somewhat stable note, propels us towards "home" at the downbeat of the next cycle.
Of course, there are other rhythmic structures that destabilize. Various types of claves (Rumba, son, African 6/8 clave), West African, Indian, and Middle Eastern rhythms contain cycling patterns of upbeat and downbeat emphases, and destabilize in their own ways.
What rhythms DO NOT destabilize? Though 3-3-2 patterns are often present in rock music (i.e. the bass and guitar strumming rhythm on R.E.M.'s Man On The Moon), the music is usually firmly grounded by the kick drum on the downbeat, and especially by the backbeat on the snare drum. For this reason, even though it's some of my favorite music, I tend to find rock music and rock drum beats to be very stabilizing, and not very propulsive in the dance studio. Maybe I just haven't worked out how to make it work yet, and it's actually a treasure trove of dance-inspiring sounds!
* Our bodies make constant, minute adjustments to remain balanced, but most of these adjustments are invisible.