(NOTE: We've updated this article with much more information from Friday evening. Please scroll down if you haven't read it all yet. Thx.)

All four members of U2 were back at work today at Electric Lady Studios in New York City, where Danger Mouse has been mixing the next U2 album.

We had a reporter on scene for a few hours in the afternoon, after Bono, The Edge and Adam Clayton had already arrived. While there, our reporter saw Coldplay's Chris Martin arrive, followed by Larry Mullen Jr. about two minutes later.

Shortly after that, a van arrived with three guitars -- each with a white label that said "U2/Edge" -- and our reporter actually helped bring the gear into the studio. (!) He saw Larry and Chris Martin together in another room before heading back outside. There was also a delivery of Ludwig drum heads; Larry's drum tech, Sam O'Sullivan, signed for that delivery.

Bono's assistant was there with what looked like a small case of clothes. The rumor is that there may be some kind of video shoot this weekend in the studio. Our reporter talked to the owner of a shop across the street from the studio, who said "they" (he thinks it was U2's crew) bought props for a video shoot. (That said, there are often lots of TV and movie shoots in New York City, so this could be anything.)

Our reporter also heard some drum tracks from outside, but no full songs, and shot this brief video of Chris Martin leaving. Martin denied he was there with U2, even though our reporter saw him and Larry together in the studio.

Word is that U2 -- or at least The Edge -- are in town until Monday, so there may be more news over the weekend.

Another fan was in the area earlier today, before our reporter showed up. Adrienne Wenner spoke to Dallas Schoo, and shared this on Twitter:

I saw my good buddy Dallas Schoo today. He said the new U2 album has a different mix. Some pop and rock. — Adrienne Wenner (@AidreenWhen) May 31, 2013

UPDATE: Shortly after we posted the above, there was more activity at Electric Lady Studios. U2 took part in a video shoot on the studio roof, doing an acoustic version of "Sunday Bloody Sunday." The video shoot apparently had nothing to do with the new album, and seems to have been instead done with people involved in the Inside Out art project. No idea when or where that video will see the light of day. Jaime Scatena, one of the people involved in the art project, shared this photo via Instagram.

After that ended, the band -- or at least Bono and The Edge -- went with the Inside Out folks to the SoHo district of New York City and gave a small, private performance. Scatena tweeted a photo of Bono and The Edge, saying "Photo: Private concert… Bono & The Edge… Wow, thanks @JR or everything! #u2 #nyc (at SoHo)."

The "@JR" mentioned above is the artist who founded the Inside Out art project in 2011 after winning a TED prize. The private performance was at his studio, and he also tweeted a photo of Bono and Edge (and Chris Martin behind them, it appears):

There's also a tweet from @KrinkNYC which says that Bono and Edge did an acoustic version of "Sunday Bloody Sunday" at JR's studio. (So that's two performances of SBS on the night.)

Last, but not least, JR himself also sent out another tweet and photo earlier from his studio.

We see Edge on the stairs right next to "The Family" sign (to the right of it), and Bono is on the left side of the photo below the sign. That might be Larry in between Bono and Edge, behind the woman in the yellow shirt. We don't see Adam anywhere in this photo.

And that, as best we can tell, is the full rundown of Friday's events.