How rappers like Jay-Z have risen from do-rags to riches.

Rap music is the defining American art form of our time. In its showmanship, its exuberance, its hunger for innovation, its love of technology and its ruthless competitive discipline, it represents mass culture in the US like no other medium.

Country music, the only other contender, showcases a different set of equally American values: community, tradition, compassion, patriotism, resilience, faith. But it is principally a domestic phenomenon, largely ignored overseas. Hip-hop, meaning rap music and its associated culture, is both a global force and a central feature of the face America presents to the world. In Russia, for example, Vladislav Surkov, the powerful aide to prime minister Vladimir Putin, keeps on his desk a picture of Tupac Shakur, the Californian rapper murdered in 1996 who has become a global icon of non-specific militancy.

Artistically, rap is often said to be in decline. Aficionados talk wistfully about a golden age, typically dated from about the mid-1980s to the mid-1990s, and now forgotten by today’s performers. Commercially, too, the music has slipped back from its peak around the turn of the millennium, with steadily declining sales through the second half of the 2000s. In 2010, though, hip-hop record sales made a comeback, and this year rappers provided eight of the 31 US chart-topping albums.

Regardless of the sales figures, hip-hop’s glamour and cultural presence are stronger than ever. In an age where blandness and lack of charisma appear to be conditions of employment for emerging rock and pop performers – only Lady Gaga shows any real individuality – hip-hop’s biggest stars include such vivid personalities as Eminem, Kanye West and Nicki Minaj. Hip-hop has also created some of America’s best-known and best-rewarded entrepreneurs, including Russell Simmons, the founder of Def Jam Recordings and now a self-help guru (estimated net worth $340m), and Sean Combs, better known by his stage names Puff Daddy or P Diddy, but also the head of a small empire with interests in clothing, television and more (estimated net worth $500m). Above all, there is Jay-Z, the phenomenally successful Brooklyn-born rapper who has had more number one albums than any other solo performer, breaking the record previously held by Elvis Presley. Shortly to become the first-ever rapper to headline a concert at Carnegie Hall, with his lyrics the subject of a course at Georgetown University, Jay-Z is emblematic of hip-hop’s passage into the American mainstream.

Together with his wife, the R&B singer Beyoncé Knowles, who occupies an equally imperial position in her market segment, he has an estimated household net worth of $750m-plus. He has described himself both as “the new Sinatra” and “the black Warren Buffett”, and although both epithets display his characteristic braggadocio, neither is entirely undeserved. His track “Empire State of Mind” has become the ubiquitous, instantly recognisable anthem for his hometown to replace “New York, New York”, while if his estimated personal fortune of $450m is still only about 1 per cent of that of the Sage of Omaha, at 42 Jay-Z is still only half Buffett’s age.

The story of how Jay-Z acquired that fortune – as the subtitle says, making the move “from street corner to corner office” – is well told in Zack O’Malley Greenburg’s slender but entertaining Empire State of Mind. Tales of how artists rose from difficult backgrounds to stardom are familiar, as are accounts of how entrepreneurs built business empires from nothing. What is striking about the Jay-Z saga is that it is both. A teenager growing up with an absent father in a tough New York housing estate in the 1980s, Shawn Carter, as he was born, became a crack dealer and continued selling even as he tried to get his music career off the ground in the early 1990s. (His performing name comes from the intersection of the J and Z subway lines near the Marcy Houses – typically dour, brown New York public housing in six-storey apartment buildings – where he grew up.) Today, as O’Malley Greenburg puts it, “As much as Martha Stewart or Oprah [Winfrey], he has turned himself into a lifestyle.” Jay-Z’s personal brand has been extended to clothes, shoes, cologne, Manhattan’s Spotted Pig restaurant and the New Jersey Nets basketball team, through licensing deals and shareholdings. The common thread is that “Jay-Z has a nose for money”. In whatever form his entrepreneurship has manifested itself, as a crack dealer, a rapper or an executive, he has had an acute sense of commercial opportunities, and the determination to exploit them to the full.

O’Malley Greenburg relates a telling anecdote about meeting John Meneilly, the trained accountant who is Jay-Z’s right-hand man. In the course of the conversation, it became clear that if Jay-Z saw no obvious commercial benefit, there was no way he would co-operate with the book. The hope that the rapper might show gratitude for some of his coverage in the past – O’Malley Greenburg writes “The Beat Report”, a music business blog for the Forbes website – seems comically naive.

One of Jay-Z’s frequent boasts is “I’m not a rapper”, implying that he is much more than that, and although he is a prodigiously talented one, he has always seen music as a way to tap other sources of income. The heart of Empire State of Mind is its depiction, helped by some good shoe-leather reporting, of the commercial deals that have enabled Jay-Z to profit from exploiting his prestige and personality. Because of his life story and his talent, Jay-Z had credibility with a huge segment of young consumers, and by picking up a product in song lyrics or a video, he could have a spectacular effect on sales. Celebrity endorsements are a well-established marketing technique but Jay-Z and his business partners such as Damon Dash – the two have now fallen out – realised that it would be much more lucrative for performers to promote their own brands, giving them an equity stake in the products they sold. In 1999, for example, Jay-Z launched his Rocawear clothing line – heavily styled sportswear, often with a prominent logo, aimed at “young hip consumers” – and made sure to promote the brand by wearing it for his public appearances. It now has annual sales of $700m.

Jay-Z’s investment in the Nets has made him a partner of the owner Mikhail Prokhorov, who has said he wants to run for the presidency of Russia. It has also delivered a spectacular return on his initial investment – reportedly $1m – thanks in part to the glow of glamour that he has brought to the previously unprepossessing club.

Steve Stoute, another sometime partner of Jay-Z, now a marketing consultant, is author of The Tanning of America, a blend of social history and business school case studies that actually works surprisingly well to show how the styles, trends and ideas of hip-hop – initially an exclusively urban, African-American phenomenon – spread to a much wider group in the US and around the world. Illustrated liberally with examples from his own career, in the music industry and marketing, advising brands such as McDonald’s, Hewlett-Packard and Wrigley’s, he explains how this movement has changed consumer attitudes and behaviour, and how some attempts to use hip-hop to sell “cool” to consumers succeed, while others fail.