First, though, we need to understand the role that dance crazes play within the broader social, emotional, and cultural zeitgeist. In the original post on the restless warm-up phase of the 15-year excitement cycle, there's a detailed explanation of why dance fever breaks out during this phase. I'm already pressed for space here, so I'll only summarize.
During the preceding vulnerable phase, people had been in a refractory state: their energy levels had collapsed into negative territory after their soaring flight during the manic phase just before that. In this refractory state, most audiences just want to numb themselves to any potential stimulation -- which would feel painful -- and prefer the ethereal, floaty dream pop style of music, whether in an indie form or a mainstream form. Even among the minority who do feel like going out to nightclubs, dance music takes on a spastic rhythm that makes it hard for the average person to move their body to.
As that refractory state ends, energy levels return to baseline -- suddenly, they're capable of stimulation, feeling restless for physical activity and social interaction. But since they're only just waking up, the motions must be simple -- warm-up exercises. They need clear rhythmic markers of when to stop the wind-up motion and begin the delivery-of-force motion in their dancing. Enter the accent on the offbeat: it guides them effortlessly through the motions. It's so easy, anyone can do it -- therefore, everyone will do it, and dance fever breaks out.
One final caveat: not all dance fever songs have an instrument that plays only the offbeat and not the main beat. However, that is the purest form since it makes the offbeat more perceptually salient. It's easier for the dancer to isolate and sync up with the offbeat if there's a dedicated instrumental cue -- a 100% correlation between hearing a certain instrument, and the arrival of the offbeat. At least, something needs to play the offbeat, and whether or not it also plays the main beat depends on just how dance-y the goal is.
* * *
This warm-up phase followed the moody, emo late '50s, and led to the manic late '60s.
The early R&B dance beat is only proto-disco, without an pronounced offbeat. But in both songs below, there is a steady cymbal on both the offbeat and main beat, unlike pop music of the '50s. "The Loco-Motion" even has an soft offbeat, although not made by its own instrument -- it's the same snare drum that plays the main beat on 2 and 4 (the "backbeat"), but with softer pressure applied. For that reason, it only plays half of the offbeats (before 2 and 4), not all of them. Still, you can hear the disco beat in a primitive form.
Bossa nova enjoyed its heyday during this period, and it too was keen on percussion accenting offbeats (e.g., Jobim's interpretation of "Agua de Beber" from 1963). It was meant to be danced to. In countries outside Brazil, bossa nova did not lead to future styles, so I'm only mentioning it in passing due to its minor historical interest here. But it was essential to the early '60s zeitgeist here as well.
I'll make a separate post covering super-danceable ska music's 15-year cycle, with peaks during the warm-up phase as well. I'm focusing on R&B now because it has the richest relationships before and after the '60s in modern dance music.
"Mashed Potato Time" by Dee Dee Sharp (1962):
"The Loco-Motion" by Little Eva (1962):
* * *
This warm-up phase followed the moody, schmaltzy early '70s, and led to the manic early '80s.
Now we're in the era of disco proper, and its characteristic beat is easy to hear (and move to). The selections below add further offbeat instruments and voices.
The intro beat of "Let's All Chant" features a triplet of claps that hit two offbeats and the main beat in between -- "and 4 and". They use a voice in the chants of "ooh-ah ooh-ah," which covers "1 and 2 and" in the rhythm. The offbeat syllable "ah" is unstressed, matching musical and linguistic weakness.
The heavy offbeat is from the hi-hat, played as two quick sixteenth notes rather than the usual single eighth note. Expanding the offbeat from just "and" for eighth notes, to "and then it's" for sixteenth notes, the hi-hat hits the "then it's" portion of the offbeat. Since those two offbeats are followed by a main beat, and the mind groups elements that are contiguous, we hear this as "da-da-DA, da-da-DA," in a galloping rhythm. All the more body-moving.
"Bad Girls" shares those features. The hi-hat plays the galloping sixteenth notes during the offbeat. Both the piano and the brass section play a chord rhythmically for the offbeat on either side of 4 (every other measure). And there's an onomatopoetic chant (alternating "toot-TOOT" or "beep-BEEP") that links the end of one measure to the start of the next ("and 1" in the count). The offbeat has the unstressed syllable of the chant, matching musical and linguistic weakness. Not to mention the maracas and whistles -- overall an intricate layering of rhythms, but still simple to move your body to, thanks to the prominent offbeat on the hi-hat.
"Let's All Chant" by Michael Zager Band (1977):
"Bad Girls" by Donna Summer (1979):
* * *
This warm-up phase followed the soft-rock, power ballad late '80s, and led to the manic late '90s.
Neo-disco -- Eurodance, house, etc. -- revived the disco rhythm, only now using a drum machine instead of a person playing a drum kit. Otherwise not a whole lot else to say about this period -- probably the most lowkey among the dance fever phases, and the one whose succeeding manic phase was the most kitschy (techno of the late '90s).
Similar to disco, "What Is Love" supplements with a keyboard rhythmically playing a chord during the offbeats on either side of 4. In "Show Me Love," there's a heavy accent on the offbeat before 3, from both the keyboard hook and the maracas.
"What Is Love" by Haddaway (1993):
"Show Me Love" by Robin S. (1993):
* * *
This warm-up phase followed the emo early 2000s, and led to the manic early 2010s.
It may be hard to remember for those who were packed into the clubs back then, but upon re-listening to the big dance hits from this period, I was struck by how little percussion there is at all. And if anything, it's on the main beat only -- I had to search high and low to find a pure dance song that had an accented offbeat for percussion. Literally every big dance artist of the day did it that way, it was the approach to rhythm during that dance fever period.
That may have been a backlash against the negative stereotype that had grown around "disco rhythm on a drum machine" -- UNH-tss, UNH-tss, UNH-tss, UNH-tss. It was so derided that people actually referred to it by its percussive rhythm -- "that's just UNH-tss music, boring". That backlash against '90s techno probably began during the early 2000s, although among the less mainstream dance groups. Loosely called electroclash, this style was percussively very sparse, minimalist, and bleak.
So by the late 2000s, the solution was to have the keyboard take over the main rhythm duties -- playing the same note, or perhaps a brief flourish, during the offbeat. This sparse, minimalist approach may be better than no rhythm at all, but it does render this period less infectiously danceable than the other dance fever periods (including the early '60s).
But not to worry -- the late 2000s also saw a fusion of disco / dance music with rock / punk music, and all of those songs played a heavily accented offbeat on the hi-hat, straight out of the original disco era. They avoided the negative association with UNH-tss music because their percussion was a person playing a drum kit, not a drum machine, and the overall sound was clearly rock rather than R&B or dance. I'll devote a whole 'nother post just to surveying that phenomenon. For now, some examples of what pure dance music sounded like back then.
Madonna had decades-old roots in dance music, and was the only one to stick closely to the disco rhythm in percussion. "Sorry" from 2005 has a standard disco beat on the drum machine, but it sounds a little too much like '90s UNH-tss music. The more authentically late 2000s hit of hers was "Hung Up," which does use a hi-hat, but only on half of the offbeats (before 2 and 4). What plays on every offbeat is instead the synth -- two identical sixteenth notes that set up the galloping rhythm before a main beat. The distinctive synth flourish, sampled from ABBA, highlights the offbeats before 4 and 1, linking one measure to the next.
(Edit: I just turned up the volume on "Hung Up," and the hi-hat does play during the offbeats before 1 and 3, but it's two quick taps on a closed hi-hat -- barely audible underneath the synth notes which are playing with the exact same rhythm and at a louder volume. The hi-hat before 2 and 4 is open when struck and rings out, allowing it to be heard over the synth notes. The conclusion is the same: the average person will only hear offbeat percussion on half the offbeats, before 2 and 4, and the synth is given priority over percussion for establishing the rhythm.)
"Just Dance" is a better representative of the time. During the verse, there is no percussion on the offbeat at all, only a bass drum for the main beats, and snare for the backbeat. The offbeats are entirely played by synths, which are not part of a melodic phrase, just rhythmic single notes or brief flourishes. The chorus does use a cymbal crash, but it sounds like it's only on the main beat, then ringing out somewhat into the offbeat (or maybe there's a quiet hi-hat on the offbeat then -- hard to tell). At any rate, no percussion dedicated to the offbeat.
"Hung Up" by Madonna (2005):
"Just Dance" by Lady Gaga (2008):
* * *
This warm-up phase follows the most emo phase of all-time, the late 2010s, and will lead to another manic phase in the late 2020s.
So far, not much to say about this very young dance fever phase. But it's worth noting that the sparse percussion of the late 2000s is gone, and we're returning to disco fundamentals, usually a single hit from the hi-hat during the offbeat. By now, dance music is no longer tainted by association with UNH-tss music from over 20 years and several cycles ago. No need for a backlash against it, no need to find alternate rhythmic solutions caused by removing almost all percussion.
"Break My Heart" adds flourishes from a rhythm guitar and string section during the chorus, making it sound even more like original disco. In "Dance Again," the dark, chopped timbre on the bass makes it sound like Justice's Cross album from 2007 (among countless other examples of the time). But that's only a superficial similarity, since the basic approach to rhythm is very different now -- back to hi-hats to accent the offbeat, rather than rhythmic synth notes.
"Break My Heart" by Dua Lipa (2020):
"Dance Again" by Selena Gomez (2020):