In the year since Jaco was announced as the first official documentary of Record Store Day, two crucial interviews occurred: Jerry Jemmott, who Jaco Pastorius idolized, connected dots on Pastorius' unique bass playing for director Paul Marchand, and Joni Mitchell agreed to sit for the camera after being resistant for four years.

"It was a really big thing for us, because we finally had a female presence," says Marchand, who started in 2011 as editor of Jaco and stepped in as director in 2012. "She tied things together. When he was coming up, she worked with him and introduced him to a lot of people, and she met him again at the end of this life. She was a hopeful, emotional throughline."

Jaco, produced and financed by Metallica bassist Robert Trujillo, is the first documentary on Pastorius, who died in 1987 at the age of 35 after revolutionizing the electric bass in his work with Mitchell, Pat Metheny and Weather Report and in leading his own ensembles. One of the most electrifying presences in jazz in the 1970s and early '80s, Pastorius was a central figure in the era when fusion was commercially viable on record and as a concert attraction: More than any other musician, he made the electric bass a melodic focal point in a band.

"Jaco had a lot of edge and attitude and an onstage presence -- that's why he moved so many people," says Trujillo. "He brought the instrument to the forefront and had a unique voice, but he was also really exciting to experience."

Pastorius suffered, however, from a bipolar condition that was not diagnosed until 1982. Periods of homelessness, battles with drugs and alcohol and alienation from musicians, friends and family followed until his death from a severe beating outside a Florida nightclub.

"Jaco is one of those guys where everybody has a different misconception of who he was and what he did," Marchand says. "We had to decide which misconception we wanted to tell."

Trujillo retraced his five-year journey with the Pastorius story, offering thoughts on the late musician's genius, the sense that he was intervening from the heavens and the power of the ocean. Jaco has its final SXSW screening on Saturday at 6:30 p.m. at the Viemo Theater.

Why Jaco Pastorius' story is significant: "Listen to All American Alien Boy by Ian Hunter. He's an iconic songwriter, a rock legend admired by so many and this bass has a signature sound. It was dynamic and worked with a voice in a way I had never heard from the bass. Same thing with Joni Mitchell. Some of my favorite stuff Jaco did was with Joni, Hejira and stuff. I never heard the bass interact with a vocal melody that way. I feel like I'm drawn to music that feels new and fresh, challenging in the way it's produced. Jaco was incredibly funky and his albums were diverse. He would have these funky songs like 'Come On Come Over' or 'River People' and then something crazy like 'Crisis' or 'Punk Jazz.' Trio of Doom was a Sid Vicious moment. And the story [of him battling bipolar disorder] is so compelling."

Getting Joni Mitchell involved: "For four years we tried to connect with her, and it was nearly impossible. You have to develop a friendship with Joni before she'll agree to anything. I was drawn to Joni because I'm a fan of her music anyway, but to get to know her is really special and she gave us an amazing, compelling interview. Kirk [Hammett] and I went up to Joni at a party, and her guitar player was somebody who grew up in the same neighborhood as me and we knew many of the same musicians. Next thing you know we're having dinner and becoming friends."

Seeing Pastorius perform with Weather Report: "The very first time was at the Santa Monica Civic Auditorium. I was 14 and didn't know much about him, what he looked like or how he performed. I was amazed. People I saw at the show were skateboarders and in the same venue you had jazz fanatics, heavy metal fanatics, punk rockers. Jaco stole the show. No disrespect to Weather Report, but when he joined the band, there was a lot more meat in the seats. [Their shows] became an experience."

Getting the film made: "I felt I could finance the project and, with a specific team, get this to the finish line. I had been living in San Francisco, and after we moved back to Los Angeles I met with Passion Pictures and a producer named John Battsek, and we officially moved forward. My role in all this was to be neutral, be Switzerland, keep the peace and make it work."

Surfing: "Paul brought the magic with the editing. In the five years we've worked on this, Paul Marchand has learned to surf, and a lot of the edits were done in Venice, California. A lot of our meetings were in the water, and it was the most therapeutic way to do this. When you catch waves and you're under the sun you feel better, you get your point across in a productive way."

How they knew the film was finished: "Each year, we thought, to a certain degree, that we were finished. And every time we would be blessed with a treasure. I almost feel like it was Jaco saying: 'Here.' It could be a box of audio cassettes that had never been heard or it could be unearthed photographs from the Sony archives that we'd find out about at a meeting with label people. I can't explain why these miracles have happened, but now I know were ready. That's why we're at SXSW, why there's a Jaco event at Hollywood Bowl this summer, and Monterey Jazz Festival will honor Jaco. All of a sudden, it makes sense."