Machine Gun Kelly is many things to many people. Some know him as a self-proclaimed “Wild Boy” with a taste for rebellion; to others he’s a sellout who crossed over to the pop world with “Bad Things.” Despite his contentious career and vocal detractors, MGK’s rapid rise to the top has been interesting, to say the least.

The rapper—born Richard Colson Baker—was first noticed in 2006 for his rapid-fire delivery. His fans subsequently crowned him Machine Gun Kelly, after the notorious Prohibition-era gangster. After making waves with a number of noted self-released mixtapes, he signed on to P Diddy’s Bad Boy Records. Since then, he’s amassed a loyal fanbase and redefined his sound over the course of three studio albums and two EPs.

Yesterday, MGK returned with his fourth LP, the punk rock-tinged Hotel Diablo. Before you take a dive into the star-studded record, look back at Kelly’s career with these five tracks.

1“Wild Boy” featuring Waka Flocka Flame

Kelly’s first major label single, “Wild Boy” featuring Waka Flocka Flame, is undoubtedly his breakout hit—but if it had been up to him and him alone, the track would’ve ended up as just another deep cut on his Half Naked & Almost Famous EP.

The rapper has admitted that he wanted to kick off his career as a “serious” rapper, a direction that label boss Diddy disagreed with. “[Diddy] was the one who encouraged ‘Wild Boy,’ he encouraged the whole thing. I was like, ‘Nah, no way, we gotta go serious with the serious stuff right now,’” Kelly told MTV back in 2012. “If we would’ve went that route, I would’ve fizzled off real quick.”

“Wild Boy,” which dropped in September 2011, ended up being the rapper’s first ever appearance on Billboard’s Hot 100 chart and has since gone double platinum.

Through the success of “Wild Boy,” MGK learned the value of a strong lead single, telling MTV that he now accepts “what it does for the people in the crowd and… what it did for my recognition.” “Maybe I should just hate every song I’m about to release,” he joked.

2“Bad Mother F*cker” featuring Kid Rock

Baker’s sophomore record, General Admission, is largely considered to be a mixed bag, with its disappointing sales—it’s his only album not certified gold⁠—and polarizing critical reviews. But it also contains one of the rapper’s favorite and most notable collaborations, the Kid Rock-assisted “Bad Mother F*cker.”

The song was never meant to feature the rock icon; in fact, it was never meant to be heard by anyone. A year and a half before the rapper finalized the tracklist for General Admission, Kelly and a friend, Earl St Clair, came up with a guitar riff that would eventually become the song’s hook. But MGK was unsure about the track and put it on the backburner, telling Billboard that he thought the melody “just sounds like we’re trying to be Kid Rock too much and we’re not.”

But unbeknownst to Kelly, his own team sent the hook to Kid Rock himself. The night before General Admission was due, his team sat him down with a huge surprise in hand.

“Everyone brought up ‘Bad Mother F*cker,’ and I was like, ‘It’s over. Don’t even fuckin’ bring it up,’” MGK told AltPress. “And they said, ‘But what if we told you that Kid Rock is on it?’ And they pressed play, and he was on it. And I wrote my verses in like five fuckin’ minutes. And now it’s legendary.”

3“Bad Things” featuring Camila Cabello

Love it or hate it, “Bad Things” was inescapable in the latter half of 2016. With a guest spot from a pre-“Havana” Camila Cabello and armed with an infectious interpolation of Fastball’s 1999 hit, “Out of My Head,” Kelly and producers The Futuristics set out to craft what would become the rapper’s most successful single ever.

The song shot for authenticity and poignant storytelling, and its creation involved constant FaceTime discussions on its direction, lyrics and the artists’ vocal delivery. According to Billboard, the former Fifth Harmony member did about 100 takes to get it just right. All their effort didn’t go to waste, though, as the song about reckless young love ended up resonating with the listening public and peaked at number four on the Hot 100.

“There’s something about America’s sweetheart and America’s bad boy,” MGK told Billboard about the song. “That juxtaposition is what everyone desires. Prior to this, it was ‘Bonnie and Clyde’ from [Jay-Z] and Beyoncé, going back further you have Romeo and Juliet.”

4“Rap Devil”

MGK might have his soft side, but if you take aim at the 28-year-old, he will fire back. Eminem learned that the hard way when he called Kelly out on “Not Alike,” one of several diss tracks on his Kamikaze album, which escalated the duo’s high-profile feud.

Kelly clapped back with “Rap Devil,” an almost five-minute-long response that’s recognized as one of the rapper’s finest work. He drops vicious bars about everything from Slim Shady’s age, his weak rap game and seeming irrelevance of the later part of his career.

The 28-year-old also doubled down on a previous allegation where he accused the “Rap God” of trying to stifle his career. “Let’s talk about the fact you actually blackballed a rapper / That’s twice as young as you,” MGK spits. “Let’s call Sway, ask why I can’t go on Shade 45 because of you / Let’s ask Interscope, how you had Paul Rosenberg tryin’ to shelf me.”

The feud whipped social media into a frenzy, with rappers like Young Thug saying that MGK “murdered” Slim Shady, and provoked a reaction from Em in the form of “Killshot.” Although their beef has simmered down as of late, one thing’s been made clear: don’t mess with MGK.

5“The Dirt (Est 1981)” by Mötley Crüe featuring Machine Gun Kelly

Earlier this year, heavy metal veterans Mötley Crüe tapped MGK for a verse for “The Dirt (Est 1981),” the band’s first release since reuniting late last year. On the glam metal track, Kelly pays homage to the legendary band’s infamously debauched lifestyle, rattling off a list of Crüe-approved vices. “Give me more sex, more tats, more blood, more pain / More threats, more theft, torn jeans, cocaine / More pretty strippers with the big red lips / Making big tips, showing off their nice big tits,” he raps.

For Kelly, who at 13 years old treated the group’s 2001 memoir, The Dirt, as his “Bible,” as he told Billboard, it was no doubt a dream come true. But MGK did more than just record with the band: He also portrayed drummer Tommy Lee in the Netflix film adaptation of the book.

Kelly’s role in The Dirt isn’t just a novelty gig, though, as striking out in Hollywood seems to be his next big career move. With films like Bird Box and Nerve under his belt, as well as upcoming roles in projects by directors Ariel Schulman and Judd Apatow, the movie world seems to have embraced MGK with open arms.

Stream Hotel Diablo here.