Long-dormant Outkast duo Big Boi and André 3000 hung out in the flesh last night, Instagramming a delicious morsel of photo evidence that's sent the Internet into another fit of will-they-won't-they, what's-up-with-André hysterics. "Here’s Photo Proof That Big Boi and Andre 3000 Are Hanging Out," reads one such headline (from Slate), and indeed they are, bumming around their old Atlanta haunts just weeks after news broke that the ATLiens of southern-fried hip hop are maybe finally definitely getting back together. Meanwhile in Portland, all three members of Sleater-Kinney "reunited" during the long holiday weekend at a Pearl Jam show. December's hardly begun, but 2014 already has the reunion tour fire burning, huh?

Wellmaybe. A quick jaunt onstage during a Pearl Jam concert does not a reunion make, and as far as Outkast's slated Coachella performance goes, do kindly recall that you can plan a picnic, but you can't predict the weather. As Grantland put it, we'll believe it when they're literally onstage at Coachella.

Still, you've a right to be confused: what even constitutes a "real" reunion? A five-minute surprise appearance during one member's solo set? An impromptu gathering at a local Cinnabon? It's blurry and there's ample room for error, but let's set some ground rules anyway: a genuine band reunion doesn't have to involve a world tour, a new album (see: Pixies, who last released a full-length LP in 1991), or even all original members. But it does need to involve at least one instance in which the group, playing under its own name, gets together onstage for the express purpose of performing a full concert (orokayat least a few songs) of its own material. Agreed?

So is this Outkast thing a reunion or what?

Well, maybe! There are still four or five months until Coachella, and these plans still seem mighty fuzzy. But even if a 'kast reunion was officially official on the books, it wouldn't be the first plan a high-profile Coachella reunion fell through in the months leading up to the big date. But think positive—it certainly may happen (and maybe we'll even get a studio LP to wash away the lukewarm taste of the Idlewild soundtrack).  

But one blurry Instagram does not an official reunion make, just as you don't see headlines about Talking Heads getting back together every time David Byrne and Chris Frantz grab lunch.

But Sleater-Kinney really reunited this weekend, right?

No, not really. More accurately, the three women who famously comprised Sleater-Kinney in the 1990s and early 2000s joined Pearl Jam onstage for a cover of Neil Young's "Rockin' in the Free World." It lasted seven or so minutes and offers no hint of future Sleater-Kinney activity, rad as that would be:

R.E.M. totally got back together last month.

This was a fairly similar situation, except it didn't involve all four members of the band—but at least they played an R.E.M. song. Singer Michael Stipe watched from the crowd as former bandmates Peter Buck, Bill Berry, and Mike Mills joined together onstage for a quick rendition of "(Don't Go Back to) Rockville" during a Buck solo set in Athens, GA. The fact that Stipe apparently didn't have it in him to hop onstage for the vocal part probably doesn't bode well for a real reunion.

So... did 'N Sync reunite at the VMAs or what?

Fine. We'll give you that one. It hardly lasted two minutes, about the time it takes you to microwave canned soup, but whatever. Take it. Take it and run.

What about the Soundgarden-run-in-at-Cinnabon thing?

Err, that's an Onion story (and a rather funny one). But the band did reunite, for real-real, some years after it ran. And they released their first album in 16 years only last year. Seems pretty legit to us.