Singer Joe Cocker, famous for his powerful and raspy voice, has died at age 70. Ron Wolfson/Landov hide caption

itoggle caption Ron Wolfson/Landov

Billie Joe Armstrong (left) and Mike Dirnt of Green Day play the Reading Festival. Green Day and five other acts will join the Rock and Roll Hall of Fame next year. Yui Mok/PA Photos/Landov hide caption

itoggle caption Yui Mok/PA Photos/Landov

Bob Marley, seen here performing in Paris in 1980, died years before Legend was released. It has since sold millions of copies — and this week, it hit No. 5 on the Billboard chart. Guidot Lou/Dalle /Landov hide caption

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Jimmy Page, Robert Plant, and John Bonham of Led Zeppelin, in 1970. A new lawsuit says the group borrowed from another band's work without crediting it, for the huge hit "Stairway to Heaven." Roger Jackson/Getty Images hide caption

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Pharrell Williams, center, performs "Happy" during the Oscars at the Dolby Theatre on Sunday, with the help of dancers who attend an L.A. high school (they're dressed in pastel colors). John Shearer/John Shearer/Invision/AP hide caption

itoggle caption John Shearer/John Shearer/Invision/AP

A map of the U.S. lists the musical acts that set states apart from each other. It's not a matter of an artist's popularity, says Paul Lamere, who made the map, but of a state's distinct preferences. Paul Lamere, Director of Developer Platform at The Echo Nest hide caption

itoggle caption Paul Lamere, Director of Developer Platform at The Echo Nest