"So how does a concert in 3D work? Basically, the band played in front of a screen that projected a series of bizarre cartoons and video clips, and the audience was given 3D glasses upon entering the venue. Even though the experience was novel, watching Primus tear through “Jerry Was a Race Car Driver” while giant cheese wedges cascade over the band is the type of visual to make any stoner grin with visceral satisfaction. It’s hard not to geek out when your watching a band like Primus while 3D bubbles bigger than the stage are engulfing the band. "
You wear 3D glasses or goggles for this. Claypool says the glasses work fine, but the goggles are a much better effect. My guess is they use polarizing technology, but maybe it is Dolby 3D. Would be nice to know.