For the still-struggling Prince & the Revolution, it was a momentous occasion: free HBO in their motel.

It was the fall of 1981 and they were touring the South to promote the album "Controversy." Not only did they get HBO, but on this particular night each had their own room — no more doubling up.

But they all wound up watching the same film on cable. "It was Orson Welles narrating a show called 'The Man Who Saw Tomorrow,' " recalled drummer Bobby Z. "It was about Nostradamus. Orson Welles said 1999 was when the world was going to end."

The next day on the ride to the concert hall, the Revolution members shared their reflections on the movie. Not Prince. He was already there, ready to reveal a cassette of a brand-new song called "1999."

The song would become a global hit while providing an iconic phrase ("I'm gonna party like it's 1999") and the title for Prince's fifth album — a pivotal commercial breakthrough for the Minneapolis star.

On Friday, Warner Bros. will release a deluxe version of "1999" featuring a remastering of the original 1982 double album, alternate versions of songs, B sides, a live record and a DVD from that year's tour and, most significantly, 35 unreleased recordings from Prince's legendary Paisley Park vault.

" '1999' is about Prince's struggle to become a star," said Z, who now performs with the reunited Revolution. "This album was the turning point."

With the arrival of this splashy, fan-craved package three years after his death, Prince is having a remarkably prolific 2019. In June, Warner Bros. delivered "Originals," featuring his unissued recordings of songs he wrote for others, including the Bangles, Sheila E and Kenny Rogers. Then last month, his unfinished memoir-turned-scrapbook, "The Beautiful Ones," debuted at No. 1 on the New York Times' nonfiction bestseller list.

Back in 1981 and '82, Prince was on fire with creativity, a 24/7 music factory churning out a fully recorded song per day, singing and playing every instrument himself as well as crafting material for the Time and Vanity 6. Not to mention having grandiose visions of a semi-autobiographical movie that would become "Purple Rain."

"Once he started on something, it would just go and go, and it was like changing tires on a moving vehicle," said Dez Dickerson, the Revolution's original guitarist.

One crucial factor for Prince's hyperproductivity after "Controversy" was a new recording studio in his house on Kiowa Trail in Chanhassen, a couple miles south from where he later built Paisley Park.

No longer did he have to worry about the cost of recording in Los Angeles, or interference from record-label executives.

"He was literally free, no longer under the watch of someone in L.A.," said Z. "He was just on a mission."

Always self-motivated, Prince doubled down after getting booed and battered with thrown objects while opening for the Rolling Stones at the Los Angeles Coliseum in October 1981.

"In hindsight, it was a rite of passage," said Z, who recalled Charlie Watts and Bill Wyman of the Stones telling him that night about how they got razzed early in their career. "Everybody has to have kind of a moment, but this was particularly vicious."

Prince flew back to Minneapolis after that gig. Dickerson had to persuade him to return to L.A. for a second Stones show they were committed to.

Bruised but not beaten, Prince had the fortitude and confidence to press on.

"The Stones show sharpened his resolve to so undeniably carve out his own niche," said Dickerson.

The massive Stones throng also gave the critically acclaimed Minnesotan a different kind of reality check: "These were the people he had to win in order to become the superstar he wanted to be," Z observed.

'Grooves were everything'

One year to the month after the Stones debacle, "1999" arrived with its purple cover hand-painted by Prince.

"The sky was all purple, there were people runnin' everywhere," the title track proclaimed.

Buoyed by the sexy hit "Little Red Corvette" and the dance-happy "Delirious," "1999" became Prince's first widespread commercial success, selling an impressive 4 million copies. That multiplatinum triumph was even more eye-opening because "1999" was a double album at a time when only established rockers like the Who, Bruce Springsteen and Pink Floyd were allowed that luxury.

Moreover, Prince indulged in uncommonly long songs. Of the 11 selections on "1999," all but two clock in at more than five minutes, with "Lady Cab Driver" and "D.M.S.R." topping eight minutes and "Automatic" stretching to 9½ minutes.

"Everything was a jam. These grooves were everything to him," Z explained. "It was about the funk, and the funk goes on and on and on. By playing so long, that means things can happen; you're not stopping your ideas, you're just finding more on the way."

When it came time for a radio single, though, Prince would edit his songs.

Said Z: "He had a brilliant touch with the razor blade" — as evidenced by the various iterations of numbers on this new deluxe package.

Challenging technology

Even though "1999" is the first Prince album on which the Revolution is credited, they contributed very little on the recording: Dickerson played a guitar solo on "Little Red Corvette," Z added percussion here and there, and keyboardist Lisa Coleman and Dickerson sang backup on a couple of tracks.

As always, Prince worked on his own, doing brave explorations with drum machines and synthesizers, and later teaching finished songs to his live band. These new musical toys didn't easily transfer to touring, however.

"This was all first- and second-generation stuff," Z pointed out. "Prince was challenging technology on that tour, for sure. It created a lot of high-wire acts."

Musically, "1999" reflected Prince's expanding influences: the British new wave of Gary Numan and Adam & the Ants; the arty synth-rock of Devo and the Cars; the unstoppable funk of James Brown and Sly Stone, and the festive horns of Earth, Wind & Fire translated to synthesizers.

Melding all these inspirations into his own sound on "1999," Prince "found a sweet spot," said Dickerson, who now runs a marketing company in Nashville. "It had a broader commercial footprint without being a sellout."

"1999" represents the full blossoming of Prince. If he seemed fearlessly dangerous and rivetingly provocative on "Dirty Mind" and "Controversy," this album and its subsequent tour ushered in a new era for Prince & the Revolution as dazzling and dynamic entertainers — dandified custom-tailored costumes instead of creative streetwear; pay-attention-to-us MTV videos, and ambitious concert staging with artful blinds, an elevator and a giant bed for simulated sex.

"We went from black-and-white to color," Z reflected. "When I saw that shiny purple trench coat, I said: Now we're in show business."

And we know where that would lead.