Wuorinen said he tried to give the menacing nature of the rugged Wyoming landscape a greater presence in the opera than in the short-story and cinematic versions.
"It is very beautiful as the film shows," Wuorinen told the AP, "but it is definitely not sentimental, it is not a romantic landscape, it's a deadly one — it's dangerous."
This forbidding natural backdrop is represented by Wuorinen's sometimes atonal style — one that presented the singers with a steep learning curve.
"The music is very challenging, there's no question about that," said Canadian bass-baritone Daniel Okulitch, who appears as one of the cowboys in the pair — Ennis Del Mar.
Love scenes between Del Mar and fellow cowboy Jack Twist, performed by American tenor Tom Randle — which caused a stir when the movie was first aired — are depicted discreetly on the opera's minimalist stage, where the starkness of the mountain is presented as a looming projection onto a white background.
Wuorinen's score makes use of a wide range of percussion instruments that convey many sounds, including the wind and rain on the Brokeback Mountain.
The work premieres at Madrid's Teatro Real opera house on Tuesday and will run until Feb. 11. It emerged from a commission made by the New York City Opera in 2008, when Gerard Mortier was general director there. When Mortier took up the post of general director at Teatro Real two years later, he brought the project with him to Madrid.