The vault at Paisley Park Studio in Minneapolis is believed to hold 8,000 unreleased songs by Prince. Only he had access to the vault.

That arrangement changed when he died on April 21, 2016, in an elevator at his complex from an accidental overdose of the opioid fentanyl. He was 57.

The acoustic Piano and a Microphone 1983 album was released in 2018 and the following year, Originals, a collection of demos of songs he penned for other artists, came out. There were also expanded versions of the albums Purple Rain, 1999 and Sign o’ the Times, with new songs and new versions of old ones.

Next month sees the release of Welcome 2 America. Together with a 32-page booklet and a recording of his 2011 concert, this new album will feature 12 songs never released before.

It is a moot point whether the man they called “the Mozart of Minneapolis” would have wanted all these songs to be released, and whether it harms his legacy.

There are other stories that tarnish his memory. In her new book Rememberings, Sinéad O’Connor recalls a visit to his LA house in 1991 that is strange to say the least. Once there, Prince tells her he disapproves of her bad language in interviews. She replies: “If you don’t like it, you can f**k yourself.” He becomes angry and suggests a pillow fight. “Only on the first thump. I realise he’s got something stuffed in the pillow, designed to hurt,” says Sinead. “He ain’t playing at all. I make a run for it.”

There were others who were less than enthusiastic. Boy George once said Prince looked “like a dwarf who’s been dipped in a bucket of pubic hair”.

That said, he was a bona fide genius, however narcissistic, who challenged the norms of gender and sexuality with his extraordinary music.

He was born Prince Rogers Nelson on June 7, 1958, at Mount Sinai Hospital in Minneapolis. His parents Mattie Shaw (a jazz vocalist) and John Nelson (a pianist and songwriter who went by the name of Prince Rogers) were both devoted Seventh Day Adventists who sent their son to Bible study classes.

He had a younger sister, Tyka Evene Nelson, and half-brother, Alfred Jackson, Mattie’s son from her first marriage. A self-taught musical prodigy, Prince could play the piano from the age of four and wrote his first song ‘Funk Machine’ at the age of seven.

His parents broke up when he was 10. Two years later he moved in with his dad because he didn’t like his new stepfather’s morality.

That said, Prince’s father subsequently kicked him out of the house when he found him in bed with a girl. He rang his father and begged him to take him back. He refused.

“I sat crying at that phone booth for two hours. That was the last time I cried,” he said.

He was shuttled between relations before he ended up with his auntie Olivia.

At 17 he lived in the basement of a friend’s home where he listened to Sly Stone, Jimi Hendrix and James Brown records, read Penthouse magazine, and with his friend Andre, formed a band called Grand Central.

At 18, he was signed by Warner Brothers from a solo demo. He released his debut album, For You, in 1978. He was 20 and played all 27 instruments on the record. He made his first television appearance singing ‘I Wanna Be Your Lover’ on American Bandstand.

He was no ordinary pop star. His 1980 album Dirty Mind featured him on the cover in stockings, a pair of briefs and a raincoat. On the album, he sang about physical intimacy with his sister (‘Sister’) and oral sex with a 18-year-old virginal bride on the way to her wedding (‘Head’).

His support performance to The Rolling Stones at Los Angeles Memorial Coliseum on October 9, 1981, has gone down in history.

Wearing nothing but black bikini briefs, heels and trenchcoat, the unknown black star was booed by a mostly white audience of 90,000 as he sang sexually explicit songs in a falsetto voice. The abuse from the crowd emboldened him and hardened his defiance.

His next album Controversy was released in October 1981, just five days later, and saw him in a coat and a cravat, wearing eyeliner and blusher. He song about world politics (‘Ronnie, Talk to Russia’), sex (‘Jack U Off’) and, on the title track, about being reduced to a skin colour or a sexuality: “Am I black or white, am I straight or gay?”

He released 1999 the next year and hit the mainstream with classics like ‘Little Red Corvette’ and the title track, which marked him out as a pop genius.

Two years, later the album Purple Rain turned him into a superstar: ‘Let’s Go Crazy’, ‘When Doves Cry’ (his first No 1 single in America), ‘I Would Die 4 U’ and the title track are timeless.

His 1987 album Sign o’ the Times remains one of his best, taking his music to the next level of meta-funk on tracks like ‘Hot Thing’, ‘Strange Relationship’, ‘Starfish and Coffee’ and the title track, which references drugs, gangs and a condition that few in mainstream culture had heard of at the time, HIV/Aids (“a big disease with a little name”).

The album had a messianic feel to it, not least because the title came from a magazine published by Seventh Day Adventists, called Signs of the Times. It encouraged readers “to lead joyful Christian lives as they await the soon return of Jesus”.

His Lovesexy album (with Prince naked on the cover) in 1988 and the soundtrack album for the movie Batman in 1989 were both belters. Diamonds and Pearls, two years later, was probably his last decent album.

From then on, Prince seemed to waste some of his creativity in contractual rows with record companies. In 1993, in another legal row, he changed his name to an unpronounceable symbol and wrote ‘Slave’ on his face.

He married dancer Mayte Garcia in 1996. Tragically, they had a son who died soon after the birth of a rare bone disorder. They divorced in 1998.

On New Year’s Eve 1999 he married Manuela Testolini and in 2000 he changed his name back to Prince. But his musical output had begun to falter.

In June 2008, he controversially pulled his show at Croke Park after over 55,000 tickets had been sold. In November of that year, when the New Yorker magazine asked his opinion of same sex marriage, he tapped his Bible and reportedly replied: “God came to earth and saw people sticking it wherever and doing it with whatever, and he just cleared it all out. He was, like, ‘Enough.’”

Prior to that you would have found it impossible to put “hophobia” and “Prince” in the same sentence.

This was an icon of the LGBTQ+ community who sang about swapping genders for the joys of lesbianism on ‘If I Was Your Girlfriend’ and sang on ‘I Would Die 4 U’, “I’m not a woman. I’m not a man. I am something that you will never understand.”

At times, he seemed sexist and misogynist, but he also wrote songs that became hits for female artists: Chaka Khan (‘I Feel for You,’ 1984), Sheena Easton (‘Sugar Walls,’ 1984), and the Bangles (‘Manic Monday,’ 1986), Sinéad O’Connor (‘Nothing Compares 2 U’, 1990).

His last Irish show was at Dublin’s Malahide Castle on July 30, 2011. I met him the month before in his suite on the fifth floor of the Bristol Hotel on Rue du Faubourg Saint-Honoré in Paris.

He said he hated contemporary music. “A lot of it sounds phoned in. It is all machines. You can’t jam with a machine. You can put your dirty clothes in a machine, but you can’t jam with it. We feel music as human beings.”

There is no doubt that Prince, however flawed as a man, moved millions of human beings with his music. In his 57 years he was both weird and inscrutable, homophobic and sexist, but his best songs remain flawless.