From Drake’s surprise mixtape to Kendrick Lamar’s highly anticipated three-year project, To Pimp a Butterfly, it’s been a notable few months for rappers. If you need to catch up, here are four rappers producing boundary-pushing content in 2015. 

Kendrick Lamar

With the release of his third album, To Pimp a Butterfly, Lamar bridges the gap between rap and social commentary better than anyone in the game. 

Lamar draws attention to social injustices in the music video for the record’s first single, “i,” and then tells listeners that his name is Uncle Sam in the album’s first song, “Wesley’s Theory.” One thing is for sure about this album: It’s different. 

It’s different than his mixtapes,differentthan Section.80, different than good kid, m.A.A.d city. Seventies funk influences are most apparent in tracks such as “King Kunta” and “These Walls,” but groovy melodies and electric bass are present throughout. 

To read a full review of Lamar's newest album, click here.

Artists you might like — Schoolboy Q, A$AP Rocky, SZA

Listen now: “i,” Kendrick Lamar

Wale

Wale deserves his self-assigned title, “Ambassador of Rap the Capital.” The District of Columbia native has been recording rap anthems for his fans since the early 2000s but didn’t release his first album, Attention Deficit, until 2009. His time in the industry boded well for his latest project, The Album About Nothing. The impressive track list features contributions from J. Cole, SZA,   Usher and, most interestingly, Jerry Seinfeld. Seinfeld’s narration is a particular highlight.

A good number of these connections were likely made with the help of British producer and DJ Mark Ronson — the man behind Amy Winehouse’s “Valerie” and Bruno Mars’ “Uptown Funk”  — who discovered Wale’s MySpace account and subsequently produced his 100 Miles & Running mixtape.

Artists you might like — J. Cole, Drake, Lupe Fiasco

Listen now: “The White Shoes,” Wale

Little Simz

Little Simz ranks as the youngest and most vibrant rapper on this list. Winner of Snoop Dogg’s most recent Underground Heat MC battle, the rapper, whose real name is Simbi Ajikawo, packs her verses with material that seems to be straight from her diary. She rarely sings beyond the necessary hooks, and it’s the experimental nature of her tracks that keeps listeners coming back.

Ajikawo, 21, is no stranger to the spotlight. Ajikawo starred in two BBC TV series, “Youngers” and “Spirit Warriors,” before pursuing her rap career on a full-time basis. With six mixtapes and a full-length album dropped in five years, Little Simz established herself as a compelling lyricist with a distinctive British accent who isn’t slowing down.

Artists you might like — Estelle, The Weeknd, GoldLink

Listen now: “Intervention,” Little Simz

Earl Sweatshirt

If you attended South By Southwest, it’s likely you or someone you knew saw Earl Sweatshirt. He performed two official shows and a number of unofficial ones to promote the release of his latest album, I Don’t Like Shit, I Don’t Go Outside: An Album by Earl Sweatshirt. Earl is one of the most enigmatic characters in the rap industry,  and this album certainly reflects that.

Fair warning: You won’t find a single clean track on this album. The beats are as dark as the lyrics, leaving you slightly concerned for Earl’s well being. It’s easy to write off a melodramatic 21-year-old, but it’s obvious he’s pushing boundaries and enjoys questioning authority.

Artists you might like — Tyler, The Creator, Frank Ocean, MF Doom

Listen now: “Grief,” Earl Sweatshirt