His publicist, Yvette Noel-Schure, released a statement confirming that the superstar died on Thursday at his home in Chanhassen.
The Carver County Sheriff's Office, which is investigating the circumstances of his death, said deputies responded to a medical call at Paisley Park Studios at around 9:45 a.m.
Arriving deputies and medical personnel found the star unresponsive in an elevator at the location. First responders administered CPR but were unsuccessful, sheriff's officials said.
Investigators said there initially appeared to be no indications of foul play or suicide, but the investigation will continue. The Midwest Medical Examiner's Office in Ramsey, Minn. said it has received Prince's body and an autopsy is scheduled for Friday.
The musician's sister, Tyka Nelson, emerged from the Paisley Park compound early Thursday evening to look at bouquets, balloons and signs left by fans of her brother, then approached the crowd of nearly 200.
Nelson told the fans that her brother "loved all of you. Thank you for loving him back."
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The singer postponed a concert in Atlanta on April 7, after coming down with the flu, and he apologized to fans for the cancellation during a makeup concert last week.
Hundreds of Los Angeles fans, many dressed in purple, turned out to a vigil/rally held in LA's Leimert Park to honor the singer and dance to his music.
Prince is widely acclaimed as one of the most inventive musicians of his era, drawing upon influences ranging from James Brown to the Beatles to Jimi Hendrix. His numerous hits included "Little Red Corvette," "Let's Go Crazy" and "When Doves Cry."
Born in 1958 as Prince Rogers Nelson, the Minneapolis native broke through in the late 1970s with the hits "Wanna Be Your Lover" and soared over the following decade with such albums as "1999" and "Purple Rain."
The title song from "1999" includes one of the most widely quoted refrains of popular culture: "Tonight I'm gonna party like it's 1999."
"You can't even calculate the impact on what he did for pop music, for pop culture, for fashion," Leah Greenblatt with Entertainment Weekly told ABC News anchor George Stephanopoulos. "I think he really was living as an artist right up until the end."
Prince was also fiercely protective of his independence, battling his record company over control of his material and even his name. For a time, he even insisted that he be called "TAFKAP," or The Artist Formerly Known as Prince, and identified with a key-like symbol.
He once wrote "slave" on his face in protest of not owning his work and famously battled and then departed his label, Warner Bros., before returning a few years ago.
Prince was inducted into the Rock and Roll of Fame in 2004.
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"He rewrote the rulebook, forging a synthesis of black funk and white rock that served as a blueprint for cutting-edge music in the Eighties," reads the Hall's dedication. "Prince made dance music that rocked and rock music that had a bristling, funky backbone. From the beginning, Prince and his music were androgynous, sly, sexy and provocative."
Music ran in his family. Prince's father played in a jazz band in Minneapolis, under the name "Prince Rogers," and his mother was the singer. Young and precocious, Prince taught himself to play the piano at age 7, the guitar at 13 and the drums at 14.
When he turned 20 in 1978, Prince released his very first album, "For You," in which he sang the material and served as his own one-man band on guitar, bass, drums, synthesizers, chimes and assorted other instruments.
In addition to his own massive hits, he also proved a source of hits for others - from Sinead O'Connor's "Nothing Compares 2 U" to Cyndi Lauper's "When You Were Mine" to "Manic Monday" for the Bangles.
Prince had been touring and recording right up until his death, releasing four albums in the last 18 months, including two on the Tidal streaming service last year.
A small group of fans quickly gathered in the rain Thursday outside his music studio, where Prince's gold records are on the walls and the purple motorcycle he rode in his 1984 breakout movie, "Purple Rain," is on display.
Prince was reported to have been hospitalized in Illinois on Friday on his way back from a concert in Atlanta. He subsequently appeared at a dance party at Paisley Park.
The white building surrounded by a fence is about 20 miles southwest of Minneapolis.
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The Associated Press contributed to this report.