“Despite a reputation for metal skewing Anglo, it doesn’t in New Mexico and never has,” Mr. Keller said. He cited the appeal in New Mexico of songs like “Indians,” the enduring 1987 Anthrax single about the marginalization of Native peoples in the United States, and the admiration that many people here have for figures like Chuck Billy, the Native American frontman for the thrash metal band Testament.

While Mr. Keller’s fusing of heavy metal and politics has earned him a lot of attention, authorities on the genre argue that the mayor is part of a global current of elected officials who have made their love of metal part of their political narrative.

“It’s not that surprising, since the first generation of die-hard metal fans is entering their 40s and 50s, rising to positions of power and obtaining political influence,” said Jeremy Wallach, a cultural studies scholar at Bowling Green State University in Ohio who specializes in the global spread of heavy metal.

Danica Roem, the pioneering transgender vocalist for the band Cab Ride Home, won a seat in November in Virginia’s House of Delegates. Farther afield, Indonesia’s president, Joko Widodo, may arguably be the world’s most powerful metalhead, listing Napalm Death and Lamb of God among his favorite bands.

Freddy Lim, the headbanging frontman of the band Chthonic, is a member of Taiwan’s parliament. And in Norway, Fenriz, a member of the black metal outfit Darkthrone, campaigned for a council seat in an Oslo suburb by posting photos of himself and his cat with the caption, “Don’t Vote For Me.” (He won anyway.)

Mr. Keller, for his part, insists that he is focusing on urgent issues in Albuquerque, including a stalled rapid transit system and luring investment to the city. His supporters note that he has begun chalking up victories, like the announcement this week by a Texas health care support company that it will hire hundreds of employees here. Mr. Keller also signed into law on Thursday a bill decriminalizing possession of small amounts of marijuana, a move aimed at refocusing police resources in the crime-weary city.

Many constituents — including some in the metal scene — aren’t holding their breath that a new mayor, even one steeped in a take-no-prisoners music culture that isn’t normally associated with establishment institutions, will be able to achieve change overnight.