The show is currently underway in London, where Dave and a slew of other artists are doing a huge concert at Wembley Stadium in honor of Hawkins -- who died earlier this year. The lineup is stacked ... with members of several iconic bands scheduled to hit the stage.

Some of those acts include ... Nirvana, Metallica, Queen, Led Zeppelin, RUSH, AC/DC and The Police. Liam Gallagher of Oasis also performed, with Dave backing him on percussion.

There were a number of emotional moments throughout the concert, which is now winding down. At one point ... Dave's voice started to crack a bit when he was talking about Taylor, but he pulled it together and carried on. Safe to say, the vibe was very bittersweet.

As you can imagine, the place was absolutely packed ... which makes total sense. The sheer number of artists on the bill for this is staggering -- which just speaks to how much TH meant to the music community. But yeah, this is a show folks definitely didn't want to miss.

It's actually the first of two tribute concerts that are going to be done on behalf of Taylor -- there's another that's scheduled in Los Angeles later this month ... and that one, too, is likely to be star-studded. Anyone who isn't there now will probably show up in L.A.

As we reported ... Taylor was found dead at his hotel in Colombia, where he was touring with his band. An official cause of death has yet to be released, but an overdose of some sort seems to be what might've killed him -- upwards of 10 different substances were found to be in his system when an autopsy was done.