Jeff Bridges has spent the better part of four decades as Hollywood’s go-to character actor. In the ’70s he drew acclaim for his understated performances in Peter Bogdanovich’s The Last Picture Show and again in 1974’s Thunderbolt and Lightfoot, both of which earned him an Oscar nod. Recent audiences, however, know him only as “The Dude,” the quintessential slacker from the Coen brothers’ The Big Lebowski.

In his latest film, Crazy Heart, Bridges plays a washed up country and western singer who finds salvation in a single mother played by Maggie Gyllenhaal. His birth name is Otis, but he prefers the name Bad Blake, and it’s no wonder why. Bad drinks too much. He’s been divorced four times, and has a 28-year-old son he abandoned when the boy was 4.

Bridges sings all of the songs in the film, which came as no surprise to his co-star.

“People ask me if it was a shock to hear Jeff sing, but people were always singing and playing music on set,” notes Gyllenhaal. “It was a tiny movie, and we were living it all the time.”

Attired in a jean-colored shirt and beat-up pair of cowboy boots, Bad travels from one dive bar to the next, the only venues that will hire him. He lives out of cheap motels and spends most of his days holed up with a bottle of whisky never far from reach.

While on the road in New Mexico he agrees to do an interview with Gyllenhaal’s Jean Craddock, a reporter for the local newspaper. The interview comes to a halt when Jean asks about Bad’s estranged son. Still, there’s the sense that this will not be the last time the two will see each other.

“Bad and Jean are true star-crossed lovers. It’s that kind of boom, love at first sight with them,” Bridges notes. “That’s how it was when I met my wife, so I kind of know how that goes.”

To channel the role of Bad, Bridges immersed himself in the world of country music, working day and night with T-Bone Burnett and Stephen Bruton, who co-wrote all but one of the film’s original songs.

“His life paralleled Bad’s in many ways,” Bridges says of Bruton, who died in May from throat cancer and whom Crazy Heart is dedicated to.

Although he was initially drawn to the human elements of the script, particularly the flawed character of Bad, it was still a challenge for Bridges to capture the essence of a musician who, at 57, had seen his best days behind him. Everything from Bad’s composed manner on stage while drunk to the weathered gruff in his voice was susceptible to cliché.

Luckily for Bridges, music has been an important part of his life since childhood (In 2000, he released an album with Michael McDonald called Be Here Soon.). And with the assistance of Burnett, he decided to first approach the character from his musical core.

“I kind of went in wanting my hand held, and T-Bone didn’t do much handholding,” he jokes of Burnett’s hands-off style. “It helped a lot that the songs were so terrific and created their own little Bad Blake country music world.”

Capturing Bad’s look came easy for Bridges, who grew a beard and kept his hair long for the role. The character’s sound, however, was somewhat of a struggle. Again, Bridges turned to Burnett for help.

“We were writing into Jeff’s voice,” says Burnett. “When you’re writing music for a movie, all of the songs grow out of the character.”

For Gyllenhaal, playing the role of Bad’s desperate love interest was one she was well prepared for.

“My experience with being a mother is so tied in with this particular movie,” says Gyllenhaal, who gave birth to her daughter, Ramona, in 2006. “I think Jean loves Bad but can’t be with him because of her son.”

Despite her judgment, Jean falls for the wayward musician, leading to some of the film’s most emotionally charged moments. There’s one scene in particular where a newly sober Bad arrives to Jean’s house unannounced and pleads for her forgiveness.

“When he comes back to her, I thought I would feel stronger in that scene than I did,” she explains. “I knew there was that feeling in Jean of ‘I wish he would touch me, I wish he’d push me over the edge here.’ But, of course, he doesn’t, he couldn’t, and that was really hard.”

Crazy Heart releases in select theaters Dec. 16.