When the punk rock-loving teenage law student Rick Rubin met party promoter Russell Simmons in 1984, few could have predicted that the unlikely duo would change the face of hip-hop forever. Rizzoli’s forthcoming tome, Def Jam Recordings: The First 25 Years of the Last Great Record Label, documents how the pair’s humble “experimental art project” went on to become the most influential label in rap history, and the genre’s first multi-million dollar empire. “They built a company that made hip-hop louder and bigger than any reasonable person might have guessed possible,” says The New Yorker’s Kelefa Sanneh, a contributor to the book. Consistently and controversially shattering industry conventions, Def Jam created rap’s first 80s pin-up in LL Cool J, saw the Beastie Boys’s iconic Licensed to Ill become one of the best selling hip-hop records of all time, and, via Public Enemy, provided the theatrical soundtrack to a black power revolution. Rubin's masterstroke was encouraging Run-D.M.C. to cover Aerosmith’s “Walk This Way,” a track largely credited with bringing rap to the mainstream. “Our inexperience and innocence allowed us to make music that went beyond the accepted norm,” says Rubin of Def Jam’s modus operandi. “Enthusiasm drove us.” Today, Def Jam’s purview extends well beyond hip-hop, boasting a roster that puts Rick Ross and Method Man side by side with pop megastars Rhianna and Kanye West. In this exclusive extract, the illustrious founders recall—with a little help from the Beastie Boys’ Adam Horowitz—how they first met.

Russell Simmons: I heard T La Rock’s “It’s Yours” [produced by Rubin] on the radio: I had a lot of records on the radio that I produced, but I didn’t know that record and it was the best. So I called up Fred “Red Alert” Cruse who hosted a pioneering rap radio show in New York. Red Alert gave me his cousin, Jazzy Jay, who gave me Rick Rubin. I met Rick at [legendary 80s New York club] Danceteria.

Rick Rubin: I met Russell at the party for Michael Holman’s TV show Graffiti Rock. Russ’s name was on all these records: Jimmy Spicer, Run-D.M.C., Kurtis Blow! I was excited to meet him. He couldn’t believe that I made “It’s Yours.”

Russell Simmons: My first impression of Rick [laughs] was that he was not a likely person to have made that record, right? It was a cool-ass record.

Rick Rubin: Russell was dressed like a substitute teacher, in a sports jacket with elbow patches, and penny loafers, drinking screwdrivers. I remember he was really funny and fun to talk to; full of energy. I really liked him.

Adam Horovitz: Rick must have been blown away when he met Russell. Rick put on this funny act—all that fake wrestling stuff—but Russell was that person. Just a crazy, wild dude. One time Rick and Russ were at this restaurant. Russ was trying to get attention from the waitress, but nobody’s giving him anything. So he throws his glass on the floor and shatters it, and says, “Now do I have your attention?” That kind of thing.

Russell Simmons: Rick and I were a good marriage because he had fresh ears and he affirmed that what I was doing had greater legs than even I thought. Remember when Run-D.M.C. wanted to make [Aerosmith’s] “Toys in the Attic”? We thought “Toys in the Attic” was the name of the band. We’d never heard of Aerosmith. And in 1986 he made “Walk This Way.” So there’s his brilliance: he came from another culture and brought more to broaden the ideas that we had.