The sound of the tropics runs through Carter Burwell's score to "Before Night Falls," Julian Schnabel's film about the ill-fated Cuban writer Reinaldo Arenas. And it was just that exoticism that appealed to Burwell, one of Hollywood's most prolific composers.

Though he has scored such diverse efforts as "Gods and Monsters" and "The Velvet Goldmine, to say nothing of every Coen brothers film, Burwell had not previously delved into these musical waters.

"One of the pleasures of working on a film like this was the exposure to Cuban music from before the revolution, which except for 'The Buena Vista Social Club' I was unfamiliar with," he says.

Burwell took an unconventional approach to his task, a sensible choice given that the famously iconoclastic Schnabel was helming.

"The source music represents what's going on in the real world that Arenas is living in," says Burwell. "My score represents the internal world of his art and mind. It reflects the music of a world Arenas wants to escape to."

But though Burwell's score effectively conjures the Cuba of the past, he says that the only genuinely Cuban element in his score is the presence of claves, a wooden percussion instrument associated with Latin American music.

"Wistful is a good description of my score," Burwell says. "I was shooting for something contemplative and reflective."

The composer says he was healthily challenged by Schnabel's approach to making a picture.

"Julian's method is different from any other filmmaker. He was a cinephile before he was a filmmaker, and there's lots of free association rather than rigid method to his movies. I felt I needed to work on this film, and I told Julian that," Burwell says.

Schnabel's hands-on involvement in every aspect of the film made for some very unusual sountrack choices as well. The music often works against the grain of what's on screen, often adding an unexpected level of poignancy.

The aural landscape ranges from Cuban musicians like Pedro Ferrez Valiente and Beny More to popular Lebanese singer Fairuz to the electronica of German artists Popol Vuh to Italian film composer Ennio Morricone to Schnabel's New York neighbors, Laurie Anderson and Lou Reed.

On the use of Fairuz's hymn "Kamata Mariyam" when Arenas is introduced to New York -- a snowy scene of lilting beauty and levity, especially given the persecution that Arenas had endured prior in Cuba -- Schnabel notes: "People think: 'why do you want to use a Lebanese singer?' But the fact is, it's emotional and New York is a melting pot and it has a very spiritual quality and it's the only moment when you feel like there's an embodiment of freedom. She's singing to God."

Adds Burwell: "Some of Julian's collaborators have been turned off by his nonstop experimental approach, but I love it. And even though very few of the experiments made it into the film as is, this freeform approach was novel. As work goes, it was fun."