The good news: 26 million people were glued to their TV sets Sunday night as heavy metal heroes Metallica gave their genre a rare appearance on network television.

The bad news: A decent portion of their must-see duet with Lady Gaga was sung into a dead microphone; (her vocals were just fine).

But with their Spinal Tap moment behind them, Metallica is heading out on a 23-date North American stadium tour in May in support of their new album “Hardwired … To Self-Destruct.” It’s their first real tour since 2009, and the album has sold nearly 2 million copies since its November release.

Presumably, all the microphones will work fine.

“A minute before we started playing, when people were checking it, it worked,” drummer Lars Ulrich told The Associated Press on Monday night. “Somewhere in between there and when we began to sing, it stopped functioning.”

Guitarist and lead vocalist James Hetfield sang the first few verses of “Moth Into Flame” into a dead microphone. Lady Gaga’s vocals into a different mic went off without a hitch, prompting Hetfield to eventually abandon his mic and run over to Gaga’s.

“The one thing my phone blew up about was how awesome it was that Gaga and James were in each other’s face, singing into the same microphone, and the energy and the spectacle came across,” Ulrich said. “Obviously James did not have an easy couple of minutes, but in some way I guess his anger and frustration translated to television.”

Metallica consistently sells large amounts of new music although Ulrich was pilloried in the early 2000s with his tirades against how internet file-sharing services like Napster were destroying the music business by conditioning consumers to expect to get all their music without paying for it. His criticism has proven prophetic as the industry continues to struggle to adapt to a new online business model that obliterated decades-old sales and distribution channels.

“I don’t know what’s going to happen when we put out a new album now,” he said. “Twenty years ago, there was a path and some expectation of what would happen. Now it’s a … crapshoot. The biggest (surprise) for me is we continue to somehow still have that revolving door of kids that come aboard. If you’re 12, 13, 14 years old and you want to jump into the world of heavy music, Metallica is your one-stop-shopping place, and I’m still so happy for that. But why it happens, I can’t tell you.”

The tour begins May 10 in Baltimore and wraps Aug. 16 in Edmonton, Canada. Each concert ticket comes with a copy of the new album, either on CD or as a digital download.

“In these crazy, bewildering, divisive times, it’s going to be fun to see everybody being brought together over the course of an evening, where everybody can put their differences aside and enjoy some music,” Ulrich said. “We’re psyched to get back out there.”

———

Follow Wayne Parry on Twitter at @WayneParryAC.