Mondo Cozmo, courtesy: Jess Lakin.

LOS ANGELES — When Josh Ostrander first released his breakthrough hit, “Plastic Soul,” fans could access a free download only from the lawyer of the artist known as Mondo Cozmo. “Plastic Soul” sampled Erma Franklin’s “Piece Of My Heart,” which went on to be a caterwauling hit for Janis Joplin in 1968. At the time, Ostrander was unsure how he would get the clearance. But he knew the song was special and just wanted it to be heard.

When label executives explained they were not going to get approval for the sample, he was extremely disappointed, but undeterred.

“We waited for the label to shut down on the Friday, then I went on to Instagram and posted it with a short video,” Ostrander explains to me, as we sit at the bar of the Troubadour in Los Angeles.

The post read: “Due to potential lawsuits we are not permitted to release this song. It was written for David Bowie. It’s about time travel. If you e-mail my lawyer, he will send you link to the download.”

Ostrander had been in his previous band, Eastern Conference Champions, for more than a decade. An indie band with three albums to its name, and a surprising number of good songs in its arsenal, ECC never quite found its audience. When he called it quits in the spring of 2015, he was heartbroken and went back to his day job as a landscape contractor.

He got his second chance at stardom when KCRW DJ Jason Bentley downloaded “Plastic Soul” via the Instagram post and immediately started playing it every day on his weekday radio show, Morning Becomes Eclectic.

“Every time he played it, I would get a few hundred e-mails on my phone,” Ostrander says. “I was so amazed that this sort of thing still happens; the power of radio.”

Tonight, as he chats before his sold-out headlining show at The Troubadour, he is relaxed. It’s all a dream coming true for him. “It’s part of my 20-year plan; this is the 19th year,” he jokes.

He never stopped writing music after he quit ECC and a year later he landed a record deal as a solo artist. He credits watching Jack White at Coachella in 2015 for setting him on the solo artist path and being his own boss.

Earlier on this evening, as Ostrander walked through the venue’s bar, he happily greeted employees and patrons: “Hi! I’m Mondo.” His handshake was warm but firm, and he made an effort to express his gratitude to gushing fans. Ostrander sports a Mohawk-cut, speaks with a Philly accent and refers to his father as ‘my pops.’ He wakes up at 5 a.m. each day to write songs. He considers his previous landscaping gig an honorable job.  His salt-of-the-earth charm recalls Bruce Springsteen, the best of the working class  musicians.

He moved from the city of Brotherly Love to the City of Angels when his old band landed a major label contract. Ostrander says he loves L.A., where he and his wife, musician Aria Pullman, have carved out a pleasant life. However, it hasn’t always been this cozy.

When he performs on stage later that evening, he will dedicate several songs to his wife, much to the chagrin of the woman nearby, who remarks that he should stop mentioning Pullman. Ostrander does not take kindly to other people’s bad advice. He sticks to his guns about the songs he writes. He is not shy about his age or the fact that he has toiled in obscurity for almost 15 years, during which his wife supported him financially, oftentimes as he bottomed out emotionally.

“Hold On To Me” was written for her when he was at a particular low point. He had quit ECC just after the release of its third album, and was holding down two landscaping jobs. On a job at UCLA, a coworker pointed out that one of the college kids was wearing an ECC T-shirt. It was heartbreaking to him.

“I didn’t know if I was going to be able to do this music thing, it was a dark time,” he says. “The song was really a love letter to my wife. … I just wrote and recorded the song and got her to sing vocals on it. Later on, it was Aria that suggested we get Anna Faris to do the video for ‘Hold On To Me.’”

Faris and her husband, actor Chris Pratt are friends with Pullman and Ostrander. Ostrander wrote the theme song to her popular celebrity podcast “Anna Faris Is Unqualified,” and has appeared on it several times.

The idea for the video, where Farris dances with seniors, originated with his childhood experiences of spending time at a retirement home, where his father was the administrator.

“Anna was so nice about it,” he says. “She said: ‘I’ll do whatever you want me to.’”

Ostrander’s star continues to ascend. Whenever he hits a milestone like headlining the Mercury Lounge or Troubadour, he posts on Instagram how he’s “opened for shit bands” at these hallowed venues. With the radio chart success of “Shine,” the popularity of the “Hold On To Me” video, and the response to “Plastic Soul,” his record label skipped the customary introductory EP and asked Ostrander for a full-length. With all the momentum behind Mondo Cozmo, the label even agreed to now pay for the Franklin sample.

Currently, on tour with U.K. band Bastille, Ostrander and his entourage have upgraded from dinky vans to the ultimate ‘making-it-big’ accoutrement: the full-size bus. he wrote and recorded the LP in two weeks, and that will be released to coincide with his summer shows. Mondo Cozmo will appear on several festival bills this summer, including Outside Lands. It’s another milestone to cross off his list.

“Yes, I don’t have to work as a landscape contractor anymore,” he laughs. “It’s now just, full-time rock star.”