*NSYNC Reunion with Justin Timberlake in L.A. Came Together Quickly

Justin Timberlake performed in L.A. ahead of his new album — and wouldn’t you know it, the *NSYNC guys joined him onstage … something they cooked up in record time.

The singer hit the stage Wednesday at The Wiltern, where JT did a one-night-only show to plug his album “Everything I Thought I Was,” which drops Friday. Of course, the dude wanted to make a splash …  and did exactly that by morphing into a boy band again.

Joey Fatone, Lance Bass, JC Chasez, and Chris Kirkpatrick went up with Justin for a suprrise moment in a major highlight of the night … where they sang some *NSYNC classics.

Of course, they also belted out their new song together from Justin’s album, “Paradise,” so it was a blend of old and new tunes. In terms of how this came together, sources with direct knowledge tell TMZ JT called all the guys Sunday to see if they’d be down for this.

As it turns out, they absolutely were and ran through a couple rehearsals on Tuesday. The DJ portion of their mini set was more so done on the fly … with them wanting to lean into the nostalgia, which they knew the fans would love. As you can see in these clips, they did!

Pretty cool moment, no doubt … and it definitely generates some buzz for JT’s ‘EITIW.’

While some might assume these *NSYNC collabs could be a signal of more music from them to come — we’ve been hearing for months now that that’s not necessarily the case. We know everyone is open to doing a full-blown reunion thing … but for now, it ain’t in the cards.