'G-Eazy talks about what it's like to be a white rapper again." He says it under his breath, just as the conversation has come to an end, in a tone halfway between exasperation and resignation. I'd been trying not to ask G-Eazy, born Gerald Earl Gillum, directly about white rappers. But he knew that you might look at the way he's dressed, in his black leather biker jacket with slicked-back hair and sharp cheekbones, and think – hang on, this guy looks like James Dean but he's making songs like Drake; isn't that a bit weird? It's not weird to him; he's a rapper and always has been. But the subject hangs in the air all the same.

"Elvis gone be the face of hip-hop," is how veteran Houston rapper Scarface described it last year, meaning the feeling among the black hip-hop community that, after 30-odd years, their music had become acceptable enough to white America that it could be incorporated completely into the mainstream. That anxiety has been expressed before, when Vanilla Ice's Ice Ice Baby became the first hip-hop song to top the Billboard charts in 1991, or when Eminem became the biggest artist in rap a few years later. But while Ice was a one-hit wonder and Eminem an exceptional talent, there is a case for saying things are different now. After all, it was the pop-rap of Macklemore & Ryan Lewis that won the best rap album at this year's Grammys ahead of Drake and Kendrick Lamar, and it's the pop-dance-rap of the Australian Iggy Azalea, particularly her hit Fancy, that dominates the sound of this summer.

G-Eazy's music is not like Macklemore's or Iggy Azalea's. It is discernibly hip-hop, set to a slow southern rhythm, with trap percussion and woozy synth effects. Yes, it has sung choruses, but then what doesn't? If anything, G-Eazy's music is the product of a quintessentially hip-hop approach: seeing what's currently popular on the scene and, with the addition of a slight twist, aping it. It is an enterprising attitude and one that comes easily to Eazy. "I wasn't a natural," he says. "I wasn't like a Mozart, who just sat down, you know, and made The Chronic 2001 the first time I tried to sit in front of a computer. But it was a passion, I was overnight in love with it. And I've always had this drive, this entrepreneurial spirit inside of me, so music became a vehicle for that. I knew I wanted to do something, and create something on my own, and become somebody and build a brand and all this."

Ah, the B-word. But Eazy had been building his brand for 10 years before this summer's debut album, These Things Happen, reached No 3 in the US charts. At the age of five, after his parents' separation, he moved with his mother to Berkeley in California. He grew up in his grandparents' house, sharing a bedroom with his mother and younger brother. Living in one of the poorer neighbourhoods, he was introduced to hip-hop and the Bay Area hyphy sound. "I became surrounded by hip-hop as a culture and as a genre, and I just fell in love with it," he says. "When I was 12 or 13, the hyphy movement was beginning to bubble. And you had local acts such as the Federation or E-40, Mac Dre and Too Short that the local radio station would play all the time. You'd hear E40 as much as you'd hear Jay Z."

Using Reason, the music production software, he set about making hip-hop beats that were indebted to hyphy: slow, deep and overlaid with synths, then produced his own artwork using a cracked copy of Photoshop. "It was the sound I was really into," he says. "At the time I didn't realise how much of it was about drugs and ecstasy." As well as recording, he would press his own CDs, make his own artwork and try to "hustle" his music on street corners. He wasn't alone. Some of the kids from his school, Berkeley High, were part of the rap group the Pack. Now most famous for spawning independent rap star Lil B, they came from nowhere to have a Billboard hit in their teens. "I grew up with the Pack. When they released Vans it was a seeing-is-believing moment," Eazy says. "I remember when that song came out and they were selling mixtapes to people just like I was. That was the beginning of 2006 and they went from mixtapes for five dollars to appearing on MTV."

Determined to make his name, to build his brand, Eazy was ready to dedicate his life full-time to music. His mother had other ideas and a compromise was reached, with the 18-year-old heading to college in New Orleans – another city with its own brand of hip-hop culture, its own style, bounce music, and its own local hero, Lil Wayne. "I just remember going to clubs and they would drop his mixtape stuff, and everyone knew that shit word for word," he says. "I mean places went on fire when Wayne came on. So I soaked up the energy of the south for a while. I think that slowed my music down from 95-100 beats a minute to 65-75."

Within two years Eazy had got himself signed by Lil Wayne's management, but it wasn't entirely down to an encyclopaedic knowledge of hip-hop BPMs. He had recorded a song, Runaround, with local singer Greg Banks. It was based on a hook from the 60s classic Runaround Sue by Dion and the Belmonts and the video featured G-Eazy rapping about unfaithful women, his hair slicked back, in a white T-shirt and leather jacket. "I was slicking my hair back when I was in sixth grade," says Eazy now. "But I ran with it and wanted to make it my own. It's modern meets Johnny Cash."

With his new management and his slick look, he started touring across the country, supporting Lil Wayne and others, recording an album in the back of the bus after shows. "We rolled up our sleeves," he says. Of course, when he wasn't working, he was partying. "If you're not out living then you've got nothing to talk about. But if you're just living then you're not on top of your shit, and you've got to be on top of your shit."

Then, finally, came the major label deal with RCA and the release of These Things Happen, an album that is legitimately hip-hop, but commercial with it. The songs feature the slow tempo and the synths that Eazy grew up with, and the sung choruses are just like the ones Greg Banks once provided. The lyrics address late nights, debauchery and drugs (he does know about ecstasy now). Largely, though, they're about girls: girls he met but ditched; girls he's chased but who have never let him near; girls he can't be with but can't get off his mind. AT G-Eazy concerts, the front rows are mostly female. "When I see guys on the front row I'm like: 'Dude, what are you doing?'" he says. "But that's the concentrated definition of what a star should be: girls want to fuck him and guys want to be him."

There is something a bit clinical about G-Eazy, something quite transparently careerist. But he wouldn't mind that description; he knows that's what he's doing. And the truth is, that is an attitude that is perfectly in tune with hip-hop. Authenticity is less important than getting money, earning success. Or rather, it is money and success that is authentic. Ask G-Eazy about the claims that he's a white man appropriating black culture and he's straightforwardly phlegmatic. "I pay them no mind," he says. "At the end of the day, I fell in love with making music at an early age, I've been doing this for 10 years and it comes from a genuine place. I didn't grow up around all white people, I never wanted to gentrify hip-hop, I've never wanted to speak to an all-white audience. I'm just making music and I'm paying my bills."