Pop icon Prince was found dead at his home Thursday, cutting short one of music's most prodigious and influential careers.
His publicist confirmed his death at age 57 "with profound sadness," in an email to dpa.
Responding to an emergency call Thursday morning at Prince's Paisley Park mansion in suburban Minneapolis, sheriff's deputies found the musician unconscious in an elevator, Carver County Sheriff Jim Olson said. Efforts to revive him failed, and he was pronounced dead at 10:07 am.
Authorities were investigating the cause of death. Prince had reportedly been suffering from the flu, and had postponed two concerts in Atlanta for a week because of illness.
At the back-to-back rescheduled concerts April 14 he appeared to have made a full recovery, according to audience members, but on the way home he became ill enough to require a mid-flight emergency landing so he could be treated in hospital.
A law enforcement source told local news broadcaster KSTP that Prince had been treated in hospital again Wednesday.
Known reverently as the Purple One and His Royal Badness, Prince was one of the most acclaimed musicians of his generation, a producer, composer and performer famed for his inventive, gender-bending sensual style.
He charted more than 50 worldwide top 40 hits, according to the Los Angeles Times, including Little Red Corvette, 1999, Raspberry Beret, When Doves Cry and I Would Die 4 U.
Prince released 39 studio albums over his 35-year career, with his final album, the two-part HitNRun, released just last year. He won seven Grammys and an Academy Award, and was inducted to the Rock and Roll Hall of Fame in 2004.
His 1984 album Purple Rain sold 22 million copies worldwide and is ranked by critics as one of the greatest albums in the history of pop music.
In a statement, the Recording Academy celebrated Prince as "one of the most uniquely gifted artists of all time."
"Never one to conform, he redefined and forever changed our musical landscape. Prince was an original who influenced so many, and his legacy will live on forever," Recording Academy President Neil Portnow said.
US President Barack Obama mourned the loss, saying "the world lost a creative icon" with the singer's passing.
"Prince did it all. Funk. R&B. Rock and roll. He was a virtuoso instrumentalist, a brilliant bandleader and an electrifying performer," Obama said in a White House statement.
Obama reportedly hosted a private party last year at the White House at which Prince performed along with Stevie Wonder.
Prince's death came as a shock to a music world already mourning the deaths of a chorus of rock greats in the last year, including the Eagles' Glenn Frey, Motorhead's Lemmy Kilmeister, BB King, Jefferson Airplane's Paul Kantner, Earth Wind and Fire founder Maurice White and David Bowie, to whom Prince paid tribute in his final concert last week.
One of Prince's best-known proteges and romantic partners, Denise Matthews, who performed in the 1980s as Vanity, died February 15 at age 57.
Police closed roads outside Paisley Park as throngs of fans, some bearing purple flowers in tribute, came to pay their respects.
Neighbour Kari Swalinkavich struck a personal note as she told the Minneapolis Star Tribune about the pop star's generosity in the community, extendng invitations for pajama parties and even making pancakes.
"He was a magical little package," she said. "We just weren't ready to be done with that."
The First Avenue nightclub, where Prince got his start, said it would host an all-night dance party in his honour.
Minneapolis Mayor Betsy Hodges announced the city's bridges would be illuminated purple Thursday as the city mourned its favourite son.
"Prince was unapologetically different, and he made it okay for his fans to be different and to celebrate their individuality," she said on her website.
"In the days ahead, we will mourn Prince and will publicly honour his contributions. In the meantime, we have his music. And that will be with us forever."