When Big Boi and Phantogram released their self-titled EP as Big Grams, they’ll mark the latest chapter in a complicated history of two cultures that have occasionally, and sometimes uncomfortably, intertwined.

Such collaborations may date back to the ‘80s, but they’re less frequent than you think. In our post “Hip-Hop 101: Rap Rock,” we noted how rappers and rockers at the time warily eyed each other through a prism of race and class privilege. For rockers, rap was the new ghetto novelty; conversely, rock represented hipsters happy to play around with the new rap language. They were separate camps awkwardly searching for common ground.

Those distinctions clarified with the rise of alternative rock in the late ‘80s. On Sonic Youth’s “Kool Thing,” the New York City band tried to subvert their signing to Geffen Records (then known as DGC) by parodying the concept of radical chic and re-establishing their bona fides as outsiders. Chuck D shows up during the bridge, adding a “yeah” affirmation to Kim Gordon’s laconic vocals. A similar stance was struck on R.E.M.’s “Radio Song” when KRS-One dropped a verse at the end of their protest against formulaic radio programming. (Ironically, R.E.M. landed two massive pop hits that year with “Losing My Religion” and “Shiny Happy People.”) Both songs are fun, but they’re incongruent because their appeal is built on the novelty of a rock song featuring a rapper. A similar modus operandi can be heard on the Judgment Night soundtrack, which memorably paired rappers with rock artists, like De La Soul and Teenage Fanclub on “Fallin,” and Del the Funky Homosapien and Dinosaur Jr. on “Real Thing.”

Rap has its origins in dance music. Sonically, it’s closer to R&B, funk and club music than guitar-driven rock. (An early ‘90s example is Q-Tip’s verse on Deee-Lite’s “Groove Is in the Heart.”) Maybe that’s why, as indie music has become more pop and electronic in the 2000s, we’ve seen more collaborations along the lines of artists like Big Boi and Phantogram.

That wasn’t the case during the 1990s, when indie rock and hip-hop musicians defined themselves as bulwarks against the mainstream, wary of selling out. While alternative rock spanned from the Lollapalooza of angrily ironic hipster culture to the off-the-corporate-grid anomie of Modest Mouse (whose leader Isaac Brock rapped a bit in beat poetry style on “Lounge”), rap musicians valued themselves as truth-tellers of the world’s social conditions and the modern black experience and found success in spite of being defiantly anti-commercial. (See EPMD’s “Crossover” and OutKast’s “Mainstream.”) But when rap shifted toward a jiggy, business-friendly image in the late ‘90s, artists like Puff Daddy, who worked with Dave Grohl and Rob Zombie on an “It’s All About the Benjamins” remix, and Jay Z who made Collision Course with Linkin Park, broke bread with platinum-certified hard rock acts who could afford their appearance fees instead of modest-selling indie bands.

There were some exceptions. When Common collaborated with Laetitia Sadier on “New Wave,” it was a blatant attempt to expand his horizons beyond his usual, neo-soul-inflected style. Then there’s Sage Francis, who worked with Bonnie “Prince” Billy on “Sea Lion” and Jolie Holland on “Got Up This Morning,” and P.O.S, who recorded with Craig Finn for “Safety in Speed (Heavy Metal Unlike Common’s admirable effort, Francis and P.O.S’ songs are natural and relaxed, less a case of musical foreigners meeting for the first time than a group of artists blending their style into a cohesive form.

In some ways, the ever-growing sprawl of Internet culture has encouraged us to experiment with sounds and ideas that once lay beyond our familiar tastes. It’s no longer unusual to see Danny Brown make a song with Purity Ring or Samuel T. Herring of Future Islands develop an alias, Hemlock Ernst, for rap endeavors like Trouble Knows Me with Madlib. The Roots employed numerous indie singers on How I Got Over, including Angel Deradoorian, Amber Coffman from Dirty Projectors and Joanna Newsom. The pairings reflect the band’s current position, achieved partly through their role on The Tonight Show Starring Jimmy Fallon as elder statesman for left-of-center artists.

Big Boi of OutKast has long expressed a wide-ranging interest in popular music. During interviews for OutKast’s Speakerboxxx/The Love Below, he often talked about his admiration for Kate Bush. On his 2012 album Vicious Lies and Dangerous Rumors, he piled on duets with Wavves, Little Dragon, Jai Paul and Phantogram. But the results were often jarring, a clear case of the famous-rapper-meets-rock-band syndrome, and a project that seemed more fun to make than actually listen to. We’ll soon see if his Big Grams with Phantogram makes for a better experience, and if he can keep up with a millennial generation that’s quickly learning not to follow genre rules anymore.