It's impossible to write well about pop music without talking about geography. So it is no surprise that two terrific new works of cultural criticism - Peter Shapiro's history of disco, Turn the Beat Around, and Jeff Chang's hip-hop chronicle Can't Stop Won't Stop - both begin with stark accounts of the late 1960s/1970s New York that spawned these new forms.
Already a backlash was under way against the social advances made during the civil rights period. The New York senator Daniel Moynihan claimed: "The time may have come when the issue of race could benefit from a period of 'benign neglect'." In 1969 Time magazine awarded both its Man of the Year and Woman of the Year prizes to "the Middle American".
This was also an era of everyday apocalypse. Heavy industry was in decline. The lack of entry-level factory jobs made life especially hard for the hordes of poorly educated new immigrants who had come to the city after 1965. Public housing was often wretched. City planners such as Robert Moses had already ripped apart swathes of the Bronx to make way for freeways. Slum landlords there and in Brooklyn torched thousands of properties for the insurance money. The middle classes fled the bankrupt necropolis, which was so helpless that even Mother Teresa was moved to open her first mission there, in Harlem, in 1971.
It was in these petrified cityscapes that, according to Shapiro, some of the city's most marginal inhabitants - gay men, Latinos and black people - came together to create a musical subculture whose ecstatic sounds would rapidly migrate from decaying local microspaces to discotheques, shop floors and radio stations all across the world. They devoted themselves to a different kind of abandonment. In converted loft spaces, crumbling hotels and old Baptist churches, they created temporary paradises dedicated to polymorphous perversity and spiritual escape; notable clubs included the Sanctuary and the Haven. Disco was about mindful rather than mindless hedonism: it was a collective breakout from a culture of gay shame.
Shapiro proposes that the origins of this scene lay in 1930s Germany, where anti-establishment "swing kids", their politics expressed in long hair and ornate make-up, defied fascism's cultural tenets by hoofing to imported black jazz discs, spun by local disc jockeys. Three decades later, many of disco's pioneering DJs, such as David Mancuso and Nicky Siano, were of Italian origin. They played left-field rock and Congolese anthems, and used a much wider-ranging palette of sounds than many clubs use today.
Anyone who has ever swooned to Loleatta Holloway's "We're Getting Stronger (The Longer We Stay)" or even Sylvester's "You Make Me Feel (Mighty Real)" knows that the best disco evokes both joy and melancholy. It is perfect mirror-ball music, allowing dancers exquisite release from their drab daily lives and transporting them via magic carpets of bass and strings to some future loved-up universe; yet it often conveys a sense of loss and transience, a knowledge that this uprush cannot last for ever.
Shapiro is part savvy journalist, part hipster academic. He interviews some of the chief figures from the scene, makes good use of Deleuzian theory to talk about disco as a "revolution machine", and mounts a great defence of the music against the charge, from musicians such as George Clinton, that it is metronomic and inhuman. As entertaining as it is informative and polemical, his book is an excellent companion volume to Tim Lawrence's more exhaustive Love Saves the Day.
Jeff Chang is one of America's leading hip-hop journalists and a former boss of the SoleSides/Quannum label that issued crucial records by Blackalicious and DJ Shadow. His book is a deeply emotional history of a music that, even 20 years ago, was seen as a trivial phenomenon. His is a bold undertaking, one that decentres the music from the Bronx to the Caribbean.
Far from being an authentic X-ray of the African American id, hip-hop's roots lie in Kingston, birthplace of DJ Kool Herc. Scratching, toasting, versioning - many of the key features of "turntable-ology" had already been refined by reggae artists such as King Stitt, Big Youth and Lee Perry. Reggae and hip-hop were both examples of vernacular avant-gardism, combining liberation-theology yearnings with shanty-town grooves. Small wonder that they have both, in turn, functioned as a kind of musical lingua franca for dispossessed peoples all across the world.
The irony is that in the US itself hip-hop has for the most part abandoned its role as a channel for social critique. This form of music, which was once revolutionary - "CNN for black people", Chuck D once called it - is now mainstream. Its sonic inventions are unparalleled, but lyrically it has become indistinguishable from corporate brand advertising. Chang's prodigiously researched and politically sophisticated ode to a different era is not only insightful, but moving and enraging.
Sukhdev Sandhu is the author of London Calling: how black and Asian writers imagined a city, published by Perennial (paperback)