“There’s something happening here,” begins Stephen Stills in “For What It’s Worth” (Buffalo Springfield, 1967). He wants to call our attention to an outrage, but what it is, at that point, ain’t exactly clear. Nothing registers in the word “happening” because it has no bite, no kick. It has three syllables to get through, filling in the line. The point is, we’re waiting and watching. When a sense of happening does kick in is when we get to the one-syllable words “Stop! Hey! [or Children,]/What’s that sound?” Now we see that the real happening is not the ambiguous phenomenon out there in the world (the Sunset Strip riot over curfew, if anyone remembers) but our crystallizing reaction to it, our alarm.
In 2003, protesting the Patriot Act’s restrictions of civil rights after 9/11, Rickie Lee Jones makes the word “happened” happen. It’s her action hook word.
I want to know how far you will go
To protect our right of free speech
Because it only took a moment
Before it faded out of reach
Oh, tell somebody, tell somebody right now
Tell somebody what happened in the USA
I wanna read about it in the news
I wanna hear about it on TV, yeah
What happened in the USA
When they ask you what happened in the USA
The song is in an uptempo gospel rhythm that offers a choice in each measure between an even duple feel (the way “in the” divides the measure) and a shuffling triple feel (the way the second syllable of “happened” comes late, as the third of three subbeats). The unbalanced triple feel is the key to the kinetics of “happened.” “Happened” may be past tense but we feel its movement, proving that things are still happening and it’s not too late.
“Happened” is so happening in this song that I now consistently hear an extra ghost syllable in the word: when I sing the line to myself I expand “what happened” to “what’s happening” and revel in the expressive tension caused by cramming the longer word into the same space. (Jones sings “what’s happening” just once, in the second refrain, but contracts it to “hap’nin’”; no extra syllable there.) The effect is opposite to the static, regular “happening” in “For What It’s Worth,” which has no space problem.
Matter for further study: what makes “happiness” happen in a song?
 Three and a half years later, some of the same musicians will be screaming “Four dead in Ohio!” (Crosby Stills Nash & Young, “Ohio,” 1970). The Kent State happening has forced its own horrible shape on their witness to it.