August 30, 1986 photo of Joe Simmons (Run of Run-DMC) performing at Cap Centre. (Darrel Ellis/TWP Archives/Darrel Ellis/TWP Archives)

Rapper and actor Common is usually cool as a cucumber, but in 2006, he got a little nervous. He was working with Black Eyed Peas member and in-demand music producer Will.I.Am on a song for a movie soundtrack, and Will had assembled the tracks using liberal samples from Martin Luther King Jr.’s “I Have a Dream” speech.

“So this was serious, you know? Now I’m collaborating with Dr. King,” Common says. “Ain’t no playing around now. Not only do I have to be good, I can’t let down Martin Luther King.”

The fact that Common speaks of King in the present tense is telling of the personal and conversational flow to the rhymes he applied to the song “A Dream” (from the soundtrack to “Freedom Writers”). “In between the . . . hustle and the schemes / I put together pieces of a dream / I still have one,” he coolly and reverently raps before King’s voice returns to the mix.

Lately, you’d be forgiven for thinking hip-hop has always mentioned King this much — and this reverently. Since Common’s posthumous collaboration with King, MCs have been all over MLK. Sometimes it’s 50 Cent just citing his name, but others have equated King’s dream with the election of the nation’s first black president (rapper Jay-Z: “Now that that’s that, let’s talk about the future / We have just seen the dream as predicted by Martin Luther”).

Even Common was at it again a few months ago. At the White House (an invitation that caused apoplexy among certain pundits over the rapper’s controversial song about a cop killer), he performed a song from his album due in November, “The Dreamer, the Believer,” using more of King’s dream speech between verses.

But it wasn’t always like this.

“King was invisible in the early days” of hip-hop, says Michael Hill, a professor at the University of Iowa who researches racial identity and African American literature. “He wasn’t ‘sampled’ widely, even though his speeches were readily available. . . . He just wasn’t making his way into hip-hop songs. But that changed as agitation for a Martin Luther King holiday began in the 1980s.”

Stevie Wonder cited King in his cheery 1981 R&B song “Happy Birthday” (“There ought to be a law against / anyone who takes offense / at a day in your celebration”). The federal holiday for King’s mid-January birthday was signed into law by President Ronald Reagan in 1983, and the first holiday was observed in 1986 — but some states hesitated, which prompted Public Enemy’s scathing attack in “By the Time I Get to Arizona” (“The whole state’s racist / Why want a holiday? / [Expletive] it, ’cause I wanna”).

King’s voice was introduced, years before hip-hop, by an iconic DJ, Joe Gibson, known as “Jack the Rapper.” Throughout the late 1980s and the ’90s, though, the most frequent civil rights icon cited by Public Enemy and other rappers was Malcolm X.

“Once they bring out Malcolm X, King goes away again for 15 to 20 years,” Hill says. “That Public Enemy sample [of] Malcolm — ‘Too black, too strong!’ [in ‘Bring the Noise’] — it’s one of the most iconic samples in hip-hop. They patented Malcolm X as the voice that should be associated with this particular hard-edged framework, connecting the music with the notion of militancy.”

* * *

King’s absence makes sense to some. “The philosophy of nonviolent protest or redemptive suffering runs counter to the confrontational tone of so much hip-hop,” says Adam Bradley, co-editor of the groundbreaking “Anthology of Rap” (Yale University Press). “More than that, the Martin Luther King vision is harder to fit into a slogan than Malcolm’s. For Malcolm, you have ‘by any means necessary,’ catchphrases that capture, albeit imperfectly, his vision. With King, the closest we come is ‘I have a dream.’ It’s not surprising that’s one of the most prominent ways he appears in hip-hop.”

Even Common, for all of his use of King’s iconic speech, agrees. “Malcolm just represents more of the . . . the fire of hip-hop,” he said.

Not that it has to be one or the other. MCs in hip-hop frequently drop both names into the same song, often among a torrent of proper names.

“The main uses for name-dropping in hip-hop are as a simile,” Bradley says. “ ‘I’m like this person.’ Or occasional self-aggrandizement. Lil Wayne has this song [‘Playing With Fire’] where he says, ‘Assassinate me, (expletive) / ’cause I’m doing the same [expletive] that Martin Luther King did.’ That’s arguable,” Bradley says, then chuckles.

How serious are rappers when they link themselves so directly to a potent or polarizing figure?

For someone like Lil Wayne, Bradley says, “King’s name gives him the sound he wants to use. . . . It has little of the reverence,” Bradley says. “It’s delivered with a knowing sense that its audacity may resist the comparison, and through that it will nonetheless achieve the desired effect, which is to cast himself the giant.”

Sometimes the name-dropping, though, is didactic, often from artists who style themselves as socially conscious or political. King’s name is often employed as a means of teaching history to young people. Chuck D once famously referred to hip-hop as “the black CNN,” and even in today’s hyper-informational online culture, some MCs still take that role seriously.

Chicago rapper Lupe Fiasco, known for recently calling President Obama, on TV, “the biggest terrorist,” believes names are talismans, that dropping them will create ripples in the pond.

“It’s really a triumph anytime some rapper mentions his name,” Fiasco says of King. “The hope is that you say his name and some street dude in a car at a strip club smoking weed, that something triggers in him to go, ‘Now who is that guy and what did he do?’ ” Fiasco adds, “The names still carry weight in my world. Sneaking them in is very important.”

* * *

For Fiasco, there’s little sneaking going on. He opens his non-album track “BMF (Building Minds Faster)” announcing, “I think I’m Malcolm X, Martin Luther / add a King, add a Junior,” then proceeds through a list of figures he wants you to know about — “I’m Tupac, Bob Marley, Fela Kuti, Marcus Garvey . . . I’m Rev. Run . . . I’m T-Pain” — between his various critiques of social and foreign policy.

“I don’t even really break down who those guys were in the ‘BMF’ freestyle,” Fiasco says. “The names carry their own weight. Keeping them alive is all we need to do. It’s all we can do.”

Common understands this default duty of hip-hop — “Rap music in the hood plays the fatherly role,” he raps in “A Dream” — but when he was writing his rhymes to accompany King’s speech, the experience wasn’t so objective. It was personal.

His first verse describes every kind of darkness — gunshots fire from “sounds of blackness,” he’s followed by “dark clouds” and in his struggle to better himself, he says, “I just want some of your sun.” By the second verse, he’s turned introspective, speaking words as a letter to himself, telling “my story” about “tryna make it from a gangsta to a godlier role.” King’s dream becomes his own, though he initially worries he “ain’t using it for the right thing.”

“A lot of the struggle or fight that Dr. Martin Luther King was talking about was more for unity and about the rights of human beings,” Common says. “The character I took on in that song, you know, he says that fight exists in me. . . . I believe the change begins with you. You hear President Barack Obama speak and say, man, our work is just beginning. Well, our work is my work. We’ve got to take responsibility for the work. In the end, Martin’s dream starts with having a dream yourself — and then working to realize it, wherever and whoever you are.”

Conner is a freelance writer.