It's safe to say that Eminem is a good rapper. As a global superstar for coming up on 20 years, there is very little that he hasn't achieved in hip-hop, and he gets his deserved credit. But after his Trump-dissing performance on the BET Hip Hop Awards last month, there was one skill in particular that got a lot of attention.

An article in Pitchfork in the aftermath of the broadcast claimed that the entirety of Em’s four-minute-plus performance, with the attendant theatrical gestures, was made up on the spot. While Em does have a long history of rap battling—with improvised disses coming with the territory—he never publicly claimed the BET verse was off the top of his head, and the length, arc, and specificity of his tirade make it highly unlikely that it was spontaneous. (We reached out to Em’s camp for confirmation of this but, unsurprisingly, haven’t heard back).

A likely reason for this almost-certainly-incorrect assumption has to do with vocabulary. Em’s verse was referred to in most media outlets, including BET itself, as a “freestyle.” For most hip-hop fans, when they see the term “freestyle” they think of a rhyme that is (or at least appears to be) made up on the spot. But that hasn’t always been the case, and examining the changing meanings of the word is a three-decade story from the East Coast to the West and everywhere in between. You may think you know what “freestyle” means, but the truth is a whole lot weirder than just some rhymes made up on the spot.

Paul Edwards, author of the book How to Rap: The Art and Science of the Hip-Hop MC, accepted the “freestyle = improvised” equation as unthinkingly as most rap fans (and performers). But when he was writing his book, he stumbled on something he found fascinating.

“When I was interviewing rappers for my How To Rap books, a couple of the questions I asked everyone had to do with freestyling,” he tells me via email. “So when I interviewed Big Daddy Kane I was asking him about how he learned to rap and if he freestyled a lot as a way of learning. He immediately paused like I had said something that hit a nerve and he was like, “OK…what do you mean by ‘freestyle’?”

And then, Kane dropped a bomb. “Freestyle,” years before it meant making up a rap on the spot, had an entirely different meaning.

“In the ’80s when we said we wrote a freestyle rap, that meant that it was a rhyme that you wrote that was free of style, meaning that it’s not [on] a [particular] subject matter—it’s not a story about a woman, it’s not a story about poverty, it’s basically a rhyme just bragging about yourself, so it’s basically free of style.... That’s really what a freestyle is. Off-the-top-of-the head [rapping], we just called that “off the dome”—when you don’t write it and [you] say whatever comes to mind.”

A peer of Kane’s, Kool Moe Dee, confirmed this meaning in his 2003 book There’s a God on the Mic. He said that, until the 1990s, freestyling “was about how hard you could come with a written rhyme with no particular subject matter and no real purpose other than showing your lyrical prowess.” (Of course, even by this definition, Eminem's BET freestyle—a focused statement on one specific subject—is still not a freestyle.)

How, then, did that original meaning get buried, and the term “freestyle” become synonymous with going off the dome? Unlike most questions attempting to decipher artistic lineage, the answer to this one is pretty clear cut.

Michael “Myka 9” Troy is a Los Angeles rapper and a member of the influential group Freestyle Fellowship. He remembers the original meaning of “freestyle” really well, and recalls it being used in other now-less-remembered ways also: as a term in West Indian communities for a fixed-gear bicycle.

“That was called a ‘freestyle fixed,’” he recalls. “That's what freestyle was. KRS-One even mentioned it in one of his songs: ‘Riding one day/On my freestyle fixed.’”

When it comes to improvisational rap, Myka recalls it being called “off the dome” or, in some cases, by the more evocative term “sky rap.” But he was inspired by other youth culture movements he saw in the early 1990s, and decided to apply the word “freestyle” to his preferred way of rhyming.

“I didn't hear anybody refer to freestyling as improvisational rap until me and my crew did it and redefined the term freestyling,” he says. “I discovered freestyling from skateboarding as a kid, BMX and looking at Olympic trials and whatnot. Like, ‘Okay, so that's what it is. It's more of a freeform expression of your art, it's a freestyle.’ So I called a rap a freestyle, and it kind of caught on. And then it started to catch on on the East Coast too.”

The popularity of Freestyle Fellowship—Myka, Self Jupiter, Aceyalone, and P.E.A.C.E.—meant that they were soon traveling all around, including to hip-hop’s Mecca. And, as Myka says, the new name for the art of going off the top went with them. Self Jupiter recalls trips to NYC, hanging out with rappers like Talib Kweli, Busta Rhymes, and Yasiin Bey (then known as Mos Def).

Just as the art of improvisational rhyming was getting a new name, it was also gaining some new virtuosos. Terry “Juice” Parker, widely recognized as one of the greatest freestylers of all time, was originally from Chicago, but grew up in California, where he would battle other aspiring emcees during 30 second call-in segments on KIIS-FM. By the time he moved back to Chicago in 1993, the new name for what he had already been doing was well-established.

In the ensuing years, entire battling competitions that prized the ability to size up your opponent in a freestyle began to rise up. Cincinnati’s Scribble Jam was founded in 1996. In the festival’s second year, Juice would face—and defeat—a relatively unknown fellow Midwestern rapper in a now-famous battle.

Twenty years later, Juice is full of praise for Eminem’s freestyle skills.

“In terms of what he is skill-wise, he is one of the best,” Juice tells me when I reach him on the phone (During the call, in a brief display of his own freestyling skills, he inserts my name into a rhyme while demonstrating how he might freestyle in a battle setting: “I might say, ‘Shawn’s skinny, he really needs some weight gain/Can’t believe he tryin’ to fuckin’ battle with that fake chain’”). “[Eminem] is as good as me and Supernatural, or whoever they put in my category. He's great like that, but he just wasn't as consistent because he didn't make it his life. He could've done anything he wanted. He could've written opera if he wanted to, he just chose to be Eminem.”

The battle scene of the late 1990s and early 2000s extended from organized battles to impromptu ciphers at any places aspiring rappers would gather—street corners, outdoor venues, or pretty much anywhere else you could fit a small circle of people.

Columbus, Ohio rapper Blueprint was a big part of that scene, and frequently traveled with one of the most well-regarded freestylers of the era, the late Michael “Eyedea” Larsen. He and Eyedea while on tour would battle people in any city they found themselves. And in those days before the internet was in everyone’s pocket, many emcees wouldn’t realize who they found themselves up against until they heard their opponents’ distinctive voices.  For Blueprint, the process was all about “earning respect.”

“To us, freestyling and battling was about proving you were the best right then and right there,” he recalled in a 2015 interview. “You basically had to show up somewhere, size up who your guy was, find his weaknesses, and serve him. We were freestylers, but we loved battling, because it was a way to test who you were and your skill, and you would put everything on the line in that moment. That’s how we came up, and we really embraced that.”

While all of this was happening, expectations were changing. In Kane and Kool Moe Dee’s day, being able to rhyme off the dome was a skill that wasn’t particularly prized. But during the 1990s, it became an essential part of an emcee’s toolbox.

if I'm on MTV, I'mma use these 10 seconds, 20 seconds, 30 seconds to say whatever is on my mind at the time? No, 'cause I'm not a fucking dickhead

Opio, of Souls of Mischief and a part of the Bay Area’s famed Hieroglyphics crew, says that during his group’s early success in the early to mid 1990s, the expectation was that you had to be able to freestyle “in order to be a well-rounded MC.”

His groupmate Tajai remembers referring to a freestyle in the original, written sense as a “New York freestyle” at one point early on (“Not in a denigrating way, but we had to differentiate,” he clarifies.) In the early ’90s, he says, “When a rapper was talking 'bout, ‘Can I go freestyle?’ it meant that they were gonna say something off the script; it didn't necessarily mean spontaneous. But when we said it, it always meant spontaneous.”

The changes in the meaning of the term “freestyle” that were occurring on the East and West coasts were also happening down South. E.S.G., the Screwed Up Click member famous for his ability to freestyle for hours at a stretch, says that in Houston, the popularity of the word “freestyle” grew with the reach of mixtapes by DJ Screw starting in the mid-1990s—and with the appearance of non-rappers on those tapes.

“When Screw tapes got a lot bigger, everyone was like, ‘Let me spit a freestyle,’” he says. “Say there’s a guy in the neighborhood who has a bunch of money. He gets to go make him a Screw tape. He knows he’s not a rapper, but just because he spent the money to make the tape, he gets to emulate a rapper. So that’s when people would get on there and just start saying anything: ‘Man, I’m Joe/Man, I got a flow.’ That became the norm for people. They would just use that same cadence for their raps and their freestyles.”

The idea that being able to make up a rhyme on the spot was important for rappers stuck around. The rapper Kemba remembers that “It definitely was expected of you” to be able to go off the top when he began his career doing open mics in the late 2000s.  

But by that time, things had gotten a little muddled in the popular imagination. The “New York freestyle” never really went away. Rappers who were making media appearances and were asked to “freestyle” would often spit written rhymes, in no small part in order to make sure that they made the most of their time in front of a mass audience.

Tajai, despite his extensive experience rhyming spontaneously, is on board with this approach. “[If] I'm on Sirius XM, if I'm on MTV, I'mma use these 10 seconds, 20 seconds, 30 seconds to say whatever is on my mind at the time? No, 'cause I'm not a fucking dickhead, and I'm a professional rapper. I'mma throw some fuckin’ darts, 'cause I want my darts heard. I got 30 seconds for the whole known universe to hear my bars. I'm not about to say the first thing that comes to my mind.”

Juice points out that the two meanings of the word “freestyle” have always “peacefully coexisted.” But even in making that point, he prizes one meaning of the word above the other.

Hip-hop really is a peaceful thing. All of the art coexists peacefully. If they're dope, nobody cares if it's a freestyle or not.”