While April 21, 2016 is not a day that most Prince fans care to remember at all, there is much to be said for the comforts that music can bring. Possibly the only positive aspect of his tragic and untimely death is that it has begun to free up some of the music that Prince kept under lock and key for so many years.

A deluxe edition of “Purple Rain” containing a full album of unreleased material and a long out-of-print video of a 1985 concert is coming on June 9 — the tracklist leaked yesterday — and a former engineer who’d worked with the artist is trying, even though he’s been sued by Prince’s estate, to release an EP of material dating from 2006-2008 called “Deliverance”. (The release was held up by a judge Thursday, although the excellent title track remains available.)

As fans, we offer here five suggestions for what could be the next releases to be unveiled from Prince’s much-vaunted vault. Note: While “Deliverance” suggests that there’s more quality material under wraps from later in Prince’s career, we’ve heard little greatness, so this focuses on his early years. (For deeper detail on these and hundreds of other Prince songs, see the near-definitive fan site Prince Vault.)

1) “Dream Factory” (1986) — Always prolific, in the mid-1980s Prince’s creativity and song output were arguably at their all-time peak: Both with and without the Revolution, he was producing songs at such a rapid clip that he’d completed the first incarnation of this album before its predecessor, “Parade,” had even been released. “Dream Factory” — the last album he made with the Revolution — was also the first incarnation of the album that eventually became “Sign O’ the Times” (more on that shortly). Indeed, eight of the 18 songs on the final version of “Dream Factory” were included on “Sign,” but there are also many fascinating songs that either remain unreleased or are only available on the long out-of-print outtakes collection “Crystal Ball”: “Movie Star” is a hilariously goofy song where Prince plays the role of a delusional loser at a nightclub (and gives a rare look at his much-vaunted sense of humor); “In All My Dreams” is a wildly inventive neo-vaudeville song, with Prince’s voice distorted to sound like an 78 record, that features a dazzling piano solo from Lisa Coleman and a deft bassline from Brownmark; and “Crystal Ball” (the song) is among Prince’s oddest and most innovative tracks — a multi-part 10-minute solo excursion that bounds from one unexpected section to another (and also features one of the artist’s best-ever performances as a drummer). A high-quality, seemingly completed and mastered version of this album emerged on the black market in 2001 — few fans would be mad if it were released as-is.

2) “Crystal Ball” (1986) — This is where things get really complicated. By late 1986, Prince was riding high from the success of “Kiss” and the “Parade” album; had been laid low by the (deserved) critical lambasting of his “Under the Cherry Moon” film (as the successor to “Purple Rain,” it’s probably one of the weakest follow-ups in film history); and had just broken up the Revolution. Warner Bros., his label since the beginning of his career, was growing increasingly frustrated by Prince’s exploding productivity; the realities of music promotion meant record labels wanted just one album a year from even its top artists, and in this year Prince delivered at least three, progressing from “Dream Factory” to a totally separate eight-track album called “Camille” (which featured Prince singing in the sped-up voice he credited to the album’s namesake; most of its songs appeared on “Sign O’ the Times” or “The Black Album”); then, once those projects had all been scrapped, he prepared a triple album called “Crystal Ball” (which is separate from the 1998 outtakes collection bearing the same name, although a few tracks from it appeared on it).

Warner Bros. chief Mo Ostin told this reporter last year that while he and label president Lenny Waronker liked the triple album, they felt it would be far more commercially viable as a double, and Waronker convinced Prince to drop seven of the album’s 22 songs (being Prince, he added a brand-new one: “U Got the Look”) and release “Sign O’ the Times” in April of 1987. While there is significant overlap between these two albums, “Crystal Ball” is very much its own beast: It opens with a still-unreleased song called “Rebirth of the Flesh” and includes several tracks that emerged in different form in the coming years, like “The Ball” (which was overhauled to become “Eye No” on “Lovesexy”), “Joy in Repetition,” “Shockadelica” and his neo-Motown pastiche “Good Love.” It’s like “Sign O’ the Times” with a wildly experimental middle.

3) “Rave Unto the Joy Fantastic” (1989) — Before, during and after his sprawling “Lovesexy” tour in 1988, Prince worked on several incarnations of this album — which, like “Crystal Ball,” bears almost no relation to a similarly titled album (“Rave Un2 the Joy Fantastic,” released in 1999). This project was ultimately abandoned as Prince became involved in the “Batman” film (at least one song from this album, “Electric Chair,” emerged on that soundtrack), but many of its songs emerged elsewhere, like on the “Graffiti Bridge” soundtrack, “The Hits/The B-Sides” compilation and, just last year, the song “Moonbeam Levels” emerged on the “Prince 4Ever” collection.

4) Lovesexy Live ‘88 — Here’s another collection that’s basically already done. Prince’s “Lovesexy” tour was one of the most extravagant and expensive ever undertaken by any artist anywhere, with a wildly elaborate set that included a basketball court, a bed, a dazzling light show and even a small electric car that ferried Prince and drummer Sheila E. to and from the stage at the beginning and the end of the show. The final date of the European leg of the tour — Sept. 9, 1988 in Dortmund in what was then West Germany — was filmed with a multi-camera shoot and broadcast on TV all over Europe, resulting, quite naturally, in countless high-quality bootleg videos and DVDs. In the concert’s first set Prince and his whipcrack band race through dizzying medleys of hits and deep cuts — including two songs from the then-unreleased “Black Album” — before settling into a more restrained second set heavily featuring songs from the “Lovesexy” album, closing out with the usual punch of “1999” and “Purple Rain” favorites. It’s one of the most dazzling tours in popular music history; there’s no reason Prince’s estate shouldn’t benefit from sharing it with the world. Don’t believe me? Check out the first 20 minutes here; there’s an equally amazing 1986 concert recorded live on Prince’s 28th birthday in Detroit that was also broadcast on television.

5) “The Second Coming” (1981/82) — Seeking to package Prince’s live energy in the era just before MTV, Warner Bros. recorded full sets from both Prince and opening act The Time during the “Controversy” tour and assembled them into a concert film that captures an artist on the verge of greatness.