Whether written in advance or delivered off the top of the dome, freestyling remains one of the rawest forms of Hip Hop expression. In addition to crafting infectious cuts for their fans, the art form's greatest lyricists shone brightest when they delivered their hottest bars in an on-the-spot format – specifically, when it was just an artist, microphone and, in most cases, a random beat for the talent to spit fire.

Arguably, the best examples took place during an emcee's visit to a radio station, where they were provided the platform to go off and entertain the masses who tuned in. In other moments, many of those wordsmiths joined forces for fiery cyphers, adding to the excitement within the culture. And sometimes, freestyles are utilized in the heat of a traditional rap battle. No matter the format, all instances of the freestyle have elevated the almost-51-year-old art form.

In the book "How to Rap: The Art & Science of the Hip Hop MC," Big Daddy Kane gave his perspective on being able to deliver improvisational rhymes at the drop of a hat. "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," he explained. "It's basically a rhyme just bragging about yourself."

REVOLT compiled 15 examples that remain iconic to the masses because of the rappers' unique approach to the microphone. Check them out below.

1. Black Thought’s Funk Flex freestyle: “I'm sorry for your loss, it's a body dead in the car and it's probably one of yours...”

Over the instrumental for Mobb Deep’s “The Learning (Burn),” Black Thought delivered a 10-minute freestyle during a visit to HOT 97’s Funkmaster Flex. From the first two lines, The Roots frontman put on an unrelenting lyrical clinic that had social media on fire for days on end. In addition to receiving praise from peers and fans alike, Thought found himself talking about the incredible feat as a bandleader-turned-guest on Jimmy Fallon’s “The Tonight Show.”

2. Griselda’s “Fire In The Booth” freestyle: “Put on my shoes, nah, my hammer was first, bulletproof the whip I use to take my grandma to church...”

During a visit to the United Kingdom, the Griselda collective paid a visit to Charlie Sloth to take part in his popular “Fire In The Booth” series, and they did not disappoint. With Westside Gunn taking a backseat, Benny The Butcher and Conway The Machine provided viewers and listeners with the type of bars that made longtime fans and newcomers press the rewind button. While the group was already well-known in the States, the viral clip helped to raise their profile internationally.

3. JAY-Z's “Grammy Family” freestyle: “Everybody wanna be the king, then shots ring, you layin' on your balcony with holes in your dream/ Or you Malcolm X’d out, get distracted by screams, everybody get your hand off my jeans...”

During his Kingdom Come comeback campaign, JAY-Z stopped by Funk Flex to remind listeners that he’s one of the illest when it comes to rapping. For about four minutes, Hov waxed poetic about the dangers of being at the top over DJ Khaled and Kanye West’s “Grammy Family” instrumental.

4. JAY-Z and Big L’s Stretch & Bobbito freestyle: “I got a rep that make police jet, known to get a priest wet, I never beg for p**sy like Keith Sweat...”

Before he set fire to “Grammy Family,” JAY-Z joined the late Big L for a seven-minute cypher on WKCR’s “The Stretch Armstrong and Bobbito Show.” The unplanned collaboration saw the two emcees freestyling at a level of intensity that sounded like a full-on rap battle. As Dame Dash later revealed, the two artists did indeed compete against each other in Harlem prior to the show.

5. Kanye West and Pusha T’s Funk Flex freestyle: “Malice found religion, Tony found prison, I'm just tryna find my way up out this f**king kitchen...”

Pusha and Ye didn’t even need a beat for their Funk Flex freestyle, which – aside from Flex’s ad-libs -- left the studio so quiet you could hear a pin drop. Pusha kicked the cypher off with top-tier street raps before his former G.O.O.D. Music boss utilized rhymes that would later be heard on the critically acclaimed My Beautiful Dark Twisted Fantasy.

6. Vince Staples' “Sway In The Morning” freestyle: “Gun shots, let 'em know the game changed, never let no white girl call me by my slave name/ A 12 gauge in the champagne Buick and I use it, f**k this music, I'ma make a n**ga brains hang...”

While promoting his Hell Can Wait EP, Vince Staples paid a visit to Sway Calloway’s long-running morning show. As with any emcee who sits with the legendary host, the Long Beach talent had to come correct with some bars. Not only did he succeed at impressing Sway and co-host Heather B, but it was also delivered off the top of his head, adding to the moment’s value.

7. Eminem, Yelawolf, and Slaughterhouse’s BET Hip Hop Awards cypher: “Joell, yo, tell Joe I need his empty box from his old shell-toed Adidas, so I can put these babies in a fetal position/ They're gettin' elbows to the penis...”

During the Shady Records 2.0 era, Eminem appeared on the BET Hip Hop Awards for their iconic cypher segment. He was joined by Yelawolf and Slaughterhouse, which consisted of Joe Budden, Joell Ortiz, KXNG Crooked, and Royce Da 5’9”. They delivered timeless and oft-hilarious bars about Rihanna, skinny jeans, and Ouija boards over the instrumental for East Flatbush Project’s “Tried by 12.”

8. Lil Wayne’s “Rap City” freestyle: “I'm a shark in the water, yea, I swim with the big, so I don't have time to deal with Willie the Squid...”

Weezy made a few appearances on BET’s “Rap City: Tha Basement” series, and it was entertaining every time. In the above clip, the New Orleans veteran spit a freestyle over Collie Buddz’s “Come Around” and sent a shot to former labelmate Gillie Da Kid at a time when the Philly rhymer-turned-podcaster was vocal about his issues with Birdman and Cash Money Records. Wayne’s bars would later appear on his Da Drought 3 standout “Live From 504.”

9. Symba’s “L.A. Leakers” freestyle: “With so much to say, where should I start? They finally let the best-kept secret come out the vault/ I played my part, and I never took s**t to heart, so now that I got my time, you n**gas gon' let me talk...”

This was the kind of freestyle that put the artist on the map. While he’d been creating a healthy buzz on the West Coast, Symba’s freestyle for DJ Sourmilk and Justin Credible’s “L.A. Leakers” quickly went viral on social media and established him as one of the next to blow. “Oochie Wally” was never the same after this moment.

10. Drake's Funk Flex freestyle: “Young Money till the young boy dyin' out, you hear me cryin' out, you see me ridin’ out/ And if your man get to stuntin’, we’ll buy 'em out, ‘cause we be livin’ what these other rappers lyin' bout...”

When then-newcomer Drake stepped to the microphone at HOT 97, he received a healthy dose of criticism for his utilization of a Blackberry (shout out to Affion Crockett for his hilarious spoof). Not only has it become the norm to see phones in freestyles, but his boastful rhymes during that session, spit over JAY-Z's “You, Me, Him and Her” instrumental, continue to stand the test of time – especially since he moved on to achieve legendary status as one of Hip Hop’s crown bearers.

11. State Property’s “Rap City” freestyle: “Ayo J-A-D-A, Pinkett or Kiss, no matter how I look at him, I think of a chick/ No matter how I switch it up, think of an actor, kid, stick to the script, I’m a give him a clip...”

Amid a historic rap war between State Property and D-Block, the former’s Beanie Sigel brought his collective to “Rap City” to send off shots to their adversaries. While every artist who participated held their weight, it was Beanie’s opening bars that set the standard and fueled the fire for a beef that thankfully remained on wax.

12. Lupe Fiasco’s “Sway In The Morning” freestyle: “Was you gonna f**k Kanye up when you turned the mic off? ‘Cause I would have done the same thing if that n**ga tried to strike off...”

Over Raekwon and Ghostface Killah’s “Rainy Dayz (Remix),” Lupe Fiasco provided a masterclass in freestyling while hanging out with Calloway & Co. With no pre-written bars in sight, the Chicago native referenced religion, politics, Kanye’s infamous “answers” outburst, and much more in the roughly seven-minute clip.

13. Top Dawg Entertainment’s BET Hip Hop Awards cypher: “Nothing been the same since they dropped ‘Control’ and tucked a sensitive rapper back in his pajama clothes/ Ha ha, joke's on you, high-five, I'm bulletproof...”

TDE’s appearance during the BET Hip Hop Awards’ cypher segment was a defiant message to all challengers. Following an impressive opener from ScHoolboy Q, Jay Rock, Ab-Soul, and Isaiah Rashad got busy as R&B labelmate SZA looked on. Much like his contribution to “Control,” Kendrick’s jaw-dropping closeout created a schism in the culture and fueled a lifetime’s worth of competition among his peers.

14. Juice WRLD’s Tim Westwood freestyle: “Sick of the Percs, I'ma put them down, huh, run up on me, that chopper marry your a** like you got a gown on, guess you a p**sy now, huh?”

In addition to being a bona fide hitmaker, Juice WRLD was a pure, textbook freestyler in a generation where such a skill set wasn’t as abundant. Above, the late talent appeared on Tim Westwood’s now-defunct radio show and freestyled for an hour over a swath of beats from Eminem’s catalog. The bittersweet clip is proof of one of Hip Hop’s most unfortunate losses.

15. The Notorious B.I.G., Tupac Shakur, and more freestyle during Budweiser Superfest: “I got seven Mac 11s, about eight 38s, nine 9s, 10 MAC-10's, the s**t never ends/ You can't touch my riches, even if you had MC Hammer and them 357 b**ches!”

A true moment in history. Backed by DJ Mister Cee, Big Scoob, The Notorious B.I.G., Tupac Shakur, Shyheim, and Big Daddy Kane freestyled for a packed crowd in Madison Square Garden for Budweiser Superfest. Biggie and Pac’s portion of the five-minute cypher would go on to serve as an opening cut for Funk Flex and Big Kap’s classic The Tunnel compilation.