American rap music is an industry ruled by machismo. It is a place where reputations are made by shady pasts, the aura of violence and ultra-masculinity. But now an explosive new book is lifting the lid on one of hip hop's most unexpected secrets: that many people in the business are gay.

Terrance Dean, a former executive at music channel MTV, has penned a memoir of his life and times in the hip hop industry as a gay man. It is an explosive exposé of a thriving gay subculture in an aggressively male business, where anti-gay lyrics and public homophobia are common.

Perhaps not surprisingly, many in the industry are nervous about the book's publication this week, fearing that it will expose some of the top black names in music and Hollywood as secretly gay. But Dean said that his memoir was not intended as a way of outing famous people. 'I was never tempted to name any names. The book is not about outing people. I wrote it so that people realise the industry has a gay subculture and we are part of this music,' he said.

That gay hip hop subculture certainly seems to be thriving. Dean's book describes a world where many industry executives and some artists are leading secret gay lives, which are often obvious to everyone but rarely talked about. And, despite using some false names, the book contains enough information so that it will undoubtedly spark off a frenzy of speculation as to who some of the characters are in real life.

For example, Dean describes 'Lola', a singer who is a lesbian and had to keep her sexuality secret. And 'Gus', a male rap artist who appeared on television in typical 'gangsta' style yet hid a secret gay life. Then there are the other hints of big-name celebrities close to the hip hop business who are also gay. They include 'Lucas', a married A-list movie star, and 'Kareem', a leading sitcom actor.

Dean hopes that by bringing out his book he will allow a leading hip hop figure to come out as gay and thus pave the way for the notoriously homophobic industry to come to terms with its secret side. 'Within the next year I believe a major artist will come out. They are going to have to be brave but I think they can do it,' he said.

That is no understatement. Leading hip hop artists such as Eminem, DMX and Ice Cube have all been targeted by gay activists for using homophobic lyrics. One of Eminem's songs famously included the line: 'Hate fags? The answer's yes.' In his book Dean describes a world in which hip hop stars and executives often berate and denigrate homosexuals, and the use of the word 'faggot' is common place. He says that too often he let such abuse pass by, and writing a memoir was a way of making up for that. 'I am a part of this culture. I was getting by, saying it's OK when those things are said. But then I realised they are actually talking about me too,' Dean said.

There are signs that things are changing. Several leading rap artists, including top seller Kanye West, have admitted that homophobia is rampant in the industry and they have spoken out against it. West had previously spoken out against gay lyrics. There are also a handful of openly gay rappers such as Deadlee, who has held national US tours of his music and appeared on television to talk about his sexuality.

Dean, however, hopes that hip hop will soon put its homophobia behind it. He says the music changed dramatically from hip hop's roots in nightclubs and parties to a celebration of urban violence and gang life as 'gangsta rap' became the norm. Homophobia grew up alongside that musical shift as most successful artists used songs that idolised guns, drugs and crime. 'We need to get hip hop back to those party roots and away from the gangsta rap culture,' he said.

However, Dean's book shows that heterosexual rappers clearly have no monopoly on tough upbringings. Dean's book is a searing description of a tough childhood on the streets of Detroit, ironically also the home town of Eminem. His mother was a prostitute addicted to drugs who later contracted HIV.

Dean eventually suffered a childhood sexual assault from a male babysitter and ended up serving jail time in Nashville for stealing a car.

If homophobic rappers are looking for a dubious sense of 'authenticity', then they can just as easily find it in Dean's background as in the most masculine of gangsta rappers. But for Dean his purpose in writing the book was simply to shine a rare light on the most shadowed corner of some of the most popular music in the world.

'Everyone knows. It is not a secret in that sense. It is just that people do not talk about what goes on in private and who is sleeping with who. Now I hope a mainstream artist will have the courage to soon come out,' he said.

Rappers' Rants

· In his single 'Criminal' in 2000, Eminem sang: 'Whether you're a fag or a lez, Or the homosex, hermaph or a trans-vest, Pants or dress - hate fags? The answer's yes.'

· In the April 2004 issue of Playboy the American rapper made the point clearly: 'I don't like gay people around me, because I'm not comfortable with what their thoughts are.'

· Jamaican rapper Beenie Man's song 'Damn' includes lines such as 'come to execute all the gays' which led to the cancellation of several concerts in July 2006.

· American hip hop artist Kanye West spoke out against gay lyrics on MTV in 2004. He told a US magazine he 'wouldn't feel comfortable at a gay bar. I wouldn't go to a gay parade'.

Rowan Walker