The scene at the Flaming Lips show at ACL Live, Sunday, March 15, 2015. / Photo by Peter Blackstock

Everything was hitting fever pitch at 11 p.m. Sunday as Flaming Lips stormed through “Yoshimi Battles the Pink Robots” onstage at ACL Live for a Spredfast/Velocity party during SXSW Interactive. Balloons were flying, giant monsters were dancing onstage, lights were flashing, the band was thrashing, and Lips leader Wayne Coyne was exulting in the center of it all.

And then, strangely, the stage went quiet for almost 15 minutes. The couple of thousand attendees waited patiently for whatever wave of sensory explosion the band had in store next; many wondered if this was just a pregnant pause before a rumored cameo by Miley Cyrus.

As it turned out, the delay wasn’t planned; apparently it was dictated in order to literally clear the air, as the space had become rather thick with fog-machine haze. By way of apology, Coyne explained that it was simply “one of these safety precaution things that we’re all very glad exists.”

The show resumed and continued for another hour, but the momentum so passionately built up had been derailed. On the other hand, though, great musical moments followed down the stretch, including “Do You Realize,” “Spoonful Weighs a Ton” and “What Is the Light.”

Coyne hinted a few times that Cyrus might have been backstage at some point, possibly with ACL Live patron saint Willie Nelson, though if either were in the building, neither ended up taking the stage. Anyone disappointed by that would have to be content with Coyne’s signature stage move of climbing into a giant translucent hamster ball and going for a stroll along the oustretched arms of the audience. At this point, it’s a Lips concert tradition, but it’s still entertaining even if it’s no longer a surprise.

In the end, everything was just fine, and it felt like yet another chapter in what may be shaping up as a kinder, gentler SXSW. If the Lips show hit a bump and lost a little steam, it’s not a huge deal. The week ahead remains one mega-party and voyage of discovery, with lots more big events ahead. “And if you can’t get in, don’t worry about it,” Coyne advised near the end of the show. “Just have fun with your friends.”

Baltimore band Future Islands got that fun started on Sunday night with a 45-minute opening set melding indie and dance music seamlessly. Last year, the band broke out during South by Southwest, playing a string of shows that got everyone buzzing throughout the week and eventually earning them SXSW’s coveted Grulke Prize for Developing U.S. Act.