It started with electronics—televisions, radios, cassette decks, stereo receivers, anything the young Grandmaster Flash could get his hands on. A foster child, the Barbados-born, Bronx-raised Flash (born Joseph Saddler) didn’t have many friends, so he’d spend hours dissecting various objects he’d unearthed in local junkyards.

“I was a kid, but I didn’t do the normal things kids did,” he says. “I was always taking apart electronic items. That was my way. When kids went out and played, I was just trying to figure out how things worked. I was a geek.”

Flash entered the foster-care system after his mother died and his father, a track worker for the New York City subway system, split, but the latter nonetheless left an indelible imprint on him. “Daddy was a record collector, a serious collector of vinyl,” he explains. “In the household, nobody was allowed to go near the brown box or in the closet where Dad’s records lived. I watched Dad put the black disc into the brown box, and I found that to be very interesting. I used to get my behind smacked up quite a bit touching his stuff, but I would keep touching it.”

As a student at the Samuel Gompers Career and Technical Education High School in the Bronx, Flash learned more about push-pull circuits, diodes, resisters, AC/DC and capacitors. His innate curiosity fueled his drive to explore turntables, too, and by the 1970s, he’d found a way to manually extend drum solos using duplicate copies of records, placing his fingertips on the platter and moving it back and forth and counterclockwise.

“I was always around 45s and 33s—vinyl,” he says. “That was our way of playing music. Today, it’s mp3s and wavs, but back then, it was albums, 45s and 78s. So I was always around that. It’s just that the part I picked was where the drummer had a solo.”

Grandmaster Flash is credited as the inventor of the Quick Mix Theory, a fingertip-to-vinyl and crossfader technique that led to two other modern DJ practices: cutting and scratching. In the process, he gave MCs an elongated bed of beats to spit over, essentially birthing rap. But to this day, he struggles to explain what the Quick Mix Theory is.

“I’ve tried for 40 years, and it’s absolutely impossible because it’s math and science,” Flash says. “It’s something you have to see on the easel. But my being the first DJ to use the turntable as an instrument and then create the backing track for rappers to speak over, it’s very humblingâ€•it might not have worked.

“The Quick Mix Theory essentially turned DJs into musicians and human beings into rappers. My science is what did it. It created a backbeat for the rapper and allowed the DJ to play the turntable like an instrument.”

However difficult to describe, Flash’s innovations became the foundation for countless DJs who followed in his footsteps.

In the late ’70s, having immersed himself in the New York City DJ scene, he formed his own group, Grandmaster Flash & The 3MCs. The original lineup consisted of Melle Mel, Keith Cowboy and The Kidd Creole but was soon augmented by the addition of Rahiem and Scorpio. Hence Grandmaster Flash & The Furious Five.

In 1978, the sextet landed a weekly gig at Disco Fever in the South Bronx, a first for any hip-hop act. The following year, they signed a deal with Enjoy Records and released “Superappin’,” the follow-up to their first single, “We Rap More Mellow.” They continued playing parties around the boroughs, eventually catching the attention of Sylvia Robinson, founder/CEO of Sugar Hill Records, who promptly signed them to another deal.

Grandmaster Flash & The Furious Five released their Sugar Hill debut, “Freedom,” in 1980. It peaked at #19 on the R&B chart, selling more than 50,000 copies. Its successor, “Birthday Party,” also gained traction. The following year, “The Adventures of Grandmaster Flash on the Wheels of Steel”â€•a multi-deck, seven-minute live recording featuring Queen’s “Another One Bites the Dust,” Blondie’s “Rapture,” Incredible Bongo Band’s “Apache” and Chic’s “Good Times” and “Freedom”â€•represented the first time scratching and turntablism were committed to wax.

But it was 1982’s “The Message” that changed the face of hip-hop. Prior to the single’s release, rhymes were elementary and concerned relatively anodyne subject matter like girls and partying. “The Message,” produced by Clifton “Jiggs” Chase and songwriter Ed “Duke Bootee” Fletcher, spoke to the sociopolitical climate of New York City. Melle Mel, whose verse had been written two years earlier in response to the 1980 New York City transit strike, was the only member to actually appear on the song. He painted a grim yet vivid picture of the streets:

"Broken glass everywhere/People pissin’ on the stairs, you know they just don’t care/Can’t take the smell, can’t take the noise/Got no money to move out/I guess I got no choice/Rats in the front room, roaches in the back/Junkies in the alley with a baseball bat/I tried to get away but I couldn’t get far/Cause a man with a tow truck repossessed my car."

The record landed at #64 on the Pop chart. More significantly, it crystallized a shift in focus from the DJ to the MC. Soon, the booming voices of Run-DMC, Public Enemy, Boogie Down Productions and the Beastie Boys would dominate the foreground of hip-hop as the DJ took a back seat.

Grandmaster Flash & The Furious Five dissolved amid financial disputes, and Flash signed with Elektra Records. But the troupe’s contribution to the culture cannot be overstated. In 2007 it became the first rap group to enter the Rock & Roll Hall of Fame—inducted by none other than JAY-Z. It was a monumental moment for hip-hop purists around the world, one that firmly cemented Flash’s legacy.

“I just knew I had something,” he says. “I didn’t have a clue where it was going to end up, but I had faith and belief. Now I do lectures and speak to foster kids. I say to them, ‘Even if you come from a broken home, always believe you can make something big of yourself. All you have to do is believe.’ I’m a testament to that. And now the music is big businessâ€•it’s quite wonderful.”