It's hard to know what a Michael Jackson event release looks like today. For one, the King of Pop is very much dead; for another, November's impending release of Thriller 40 is the third reissue of the bestselling album. Are the vaults empty? Is the estate stingy? (This is, after all, the same Jackson estate that bizarrely changed the font on the cover, got very defensive about it, yet changed it again, with a new slipcase. Also, the upcoming Mobile Fidelity vinyl edition may have gotten the company into some uncomfortable spots about their use of digital files in vinyl transfers.)

On August 29 - what would have been Jackson's 64th birthday - the estate and Legacy Recordings announced the 10 tracks included on Thriller 40's bonus disc would be "revealed one at a time, starting after Labor Day with the last track being revealed just before release date, November 18." (Next week marks the 10-week countdown before the album is reissued.) Another 15 previously released tracks would be included on all digital editions, and can now be viewed through Apple Music; they range from a handful of known demos of familiar tracks, the ill-received remixes from Thriller 25 and a handful of 7" and 12" single versions.

This all of course begs the question: what's going to be on that bonus disc? The Second Disc felt charitable (or silly) enough to play the estate's game, and try to guess what's coming. We'll update this post as we know more, but here's our guesses.

Released material: It doesn't feel likely that Thriller 40 will feature wholly unreleased material - and with the digital bonus tracks sticking to versions of the songs from the album, it makes sense that some of the stray songs of the era might reappear here.

• "Someone in the Dark" - Written by "Thriller" writer Rod Temperton with Marilyn and Alan Bergman, this track opened and closed Michael's work on the storybook album to E.T. The Extra-Terrestrial (which is also celebrating a 40th anniversary this year). The ballad appeared on the 2001 reissue of Thriller as well as 2004's The Ultimate Collection box, so it's not the most unsafe bet.
• "Carousel" - A Michael Sembello-penned slow groove that appeared in part on that 2001 reissue of Thriller and released in full on some editions of King of Pop, a compilation celebrating Michael's birthday with different fan-voted track lists depending on territories. (America was among the only major countries not to participate in the campaign.) That full version appeared on a digital compilation after Jackson's passing, but a domestic disc release wouldn't be unwelcome for those who missed it.
• "Got the Hots" - The new track on Thriller 25, "For All Time," was claimed to stem from the Thriller sessions, which simply wasn't true. (Writers Steve Porcaro and Anthony Sherwood didn't work with each other until after that time period.) Japan got a second track, the spare, funky "Got the Hots," whose provenance was much harder to deny. Getting it stateside could be cool.
• "Can't Get Out of the Rain" - A non-LP B-side on several Thriller singles, this mostly instrumental jam is actually the back end of a disco single version of "You Can't Win," Michael's solo song in 1978's film version of The Wiz (and the first time Jackson and producer Quincy Jones worked together). It's been on compilations before, but it could be further canonized as part of a new Thriller package.

Unreleased material: There's still a reasonable chance that the Thriller 40 bonus disc could be mostly unreleased, and these tracks are likely candidates.

• "Behind the Mask" - One of the coolest MJ could've-beens of the '80s, Jackson was captivated by this Yellow Magic Orchestra tune and added lyrics to it, cutting a demo around the Thriller era. By the end of the decade, keyboard legend and Jackson collaborator Greg Phillinganes would cover it himself, and even got Eric Clapton to cut his own Phil Collins-produced version in 1986. The original demo was gussied up for 2010's Michael, the first posthumous studio album Sony released, but hearing it as first cut would be a treat. (It was apparently played recently at an event during the annual celebration of Jackson's birthday at Michael Jackson ONE, the Cirque du Soleil show featuring Jackson's music playing in Las Vegas.)
• "Starlight" - Before rewriting it to be about goblins and ghouls, Thriller's Temperton-penned title track was called "Starlight." A demo has circulated among fans for years - but has recently been scrubbed off YouTube. Coincidence?
• "Hot Street" / "Rolling the Dice" - These are two other known Temperton cuts worked on during the Thriller sessions. While they weren't considered as top-notch as the rest of the album, fans would certainly delight in anything new.
• "Niteline" / "She's Trouble" - Other than Temperton (and James Ingram, who worked with Quincy Jones to rework Michael's "P.Y.T." idea into a Top 10 hit, Thriller didn't feature many outside writers. But that doesn't mean Jackson didn't give some others a shot: "Niteline," co-written by Glen Ballard, would later come to life on The Pointer Sisters' Break Out (1983), and "She's Trouble" was co-written by Terry Britten a year or two before his "What's Love Got to Do with It" gave Tina Turner a massive comeback. (Britten and Graham Lyle would later write "Just Good Friends," a duet between Jackson and Stevie Wonder that appeared on Bad.)

Long shots: Those above 10 all feel pretty safe, but perhaps widening the angle and highlighting two great tunes Michael wrote on either side of the Thriller era could be a really unexpected boon.

• "Muscles" - named for Michael's pet boa constrictor, the King of Pop wrote and produced this sinewy, dramatic cut from Diana Ross' Silk Electric in 1982, giving her a Top 10 hit.
• "Centipede" - Another underrated groove that Michael wrote and produced for his eldest sister Rebbie in 1983, giving her a Top 40 hit.

What do you think will be on Thriller 40? Sound off below and bookmark this post to find out as we know more.

Thriller 40 (MJJ/Epic/Legacy 19658 73456-2, 2022) (Amazon U.S. / Amazon U.K. / Amazon Canada)

CD 1: Original album (released as Epic QE 38112, 1982)

1. Wanna Be Startin' Somethin'
2. Baby Be Mine
3. The Girl is Mine (Duet with Paul McCartney)
4. Thriller
5. Billie Jean
6. Beat It
7. Human Nature
8. P.Y.T. (Pretty Young Thing)
9. The Lady in My Life

CD 2: Bonus material (to be determined)

Digital extras

1. Billie Jean (Home Demo)
2. Billie Jean (Long Version)
3. Billie Jean 2008 (Kanye West Remix)
4. Beat It (Demo)
5. Beat It 2008 (feat. Fergie)
6. Wanna Be Startin' Somethin' (Demo)
7. Wanna Be Startin' Somethin' (Tommy D's Main Mix)
8. Wanna Be Startin' Somethin' 2008 (feat. Akon)
9. Human Nature (7" Version)
10. P.Y.T. (Pretty Young Thing) (Demo)
11. P.Y.T. (Pretty Young Thing) 2008 (feat. will.i.am)
12. The Girl is Mine 2008 (feat. will.i.am)
13. Thriller (7" Special Edit)
14. Thriller (Def Thrill Mix)
15. Thriller Megamix

Track 1 from Thriller (Special Edition) - MJJ/Epic EK 66073, 2001
Track 2 from Epic 12" 49-03557, 1983
Tracks 3, 5, 8 and 11-12 from Thriller 25 - MJJ/Epic/Legacy 88697 17986-2, 2008
Tracks 4 and 6 from Michael Jackson's This is It: The Music That Inspired the Movie - MJJ/Epic 88697 60674-2, 2009
Track 7 from Epic U.K. 12" promo XPR-2265, 1995
Track 9 from Epic single 34-04026, 1983
Track 10 from The Ultimate Collection box set - MJJ/Epic E5K 92600, 2004
Track 13 from Epic U.K. single A3643, 1983
Track 14 from Best Buy exclusive edition of Thriller 25
Track 15 from King of Pop (Deluxe Edition) - Epic U.K. 88697 35653-2, 2008