From left, “The O.C.” cast members Rachel Bilson, Adam Brody, Mischa Barton and Ben McKenzie arrive at the 2003 Teen Choice Awards. (Frederick M. Brown/Getty Images)

Stephanie Savage still hears people quietly sing Phantom Planet’s “California” on plane rides to the state. The elongated vowels — Californiaaa, Californiaaaaa, here we cooooome! — and delicately balanced tempo are unmistakable, even years after the song gained popularity as the theme song of “The O.C.” It’s hard not to join in.

Though Phantom Planet has since vanished, the four-season series, which Savage executive-produced alongside creator Josh Schwartz, lives on as a Hall of Famer among teen dramas. The Orange County teenagers and their rich parents were melodramatic yet oh-so-clever, their story lines far-fetched yet captivating. But on the 15th anniversary of its pilot, “The O.C.” is arguably best remembered for what Schwartz and Savage treated as its own character: the indie-rock masterpiece of a soundtrack.

“We were using music to illuminate the emotional lives of the characters,” Schwartz says.

“California,” while positive in message, certainly gets at the quiet angst of Ryan Atwood (Ben McKenzie), a troubled kid from Chino whom the affluent Cohen family takes in. Lead singer Alex Greenwald’s voice wavers with the uncertainty of fan-favorite dork Seth Cohen (Adam Brody), and resident whiny girl Marissa Cooper (Mischa Barton) is more than deserving of that weary ohhh.

The song came out the year before the pilot aired, and Schwartz says the team selected it so they could present Fox executives with a tune they would find familiar. It turned out nobody had heard the song before, but they “responded to it” — an experience that characterizes a good chunk of the show’s overall soundtrack.

For early episodes, Schwartz pulled much of the somewhat obscure music off his iPod. When he had used up everything worthy, they switched to Savage’s.

“Stuff like Jeff Buckley or Spoon, it was all bands we were listening to,” Schwartz says. “It also worked to our advantage — and this is where it feels a bit like a history lesson — because ‘indie’ was cheaper to license.”

Music supervisor Alexandra Patsavas, who hopped onboard around the series’ eighth episode, has since worked for popular shows like “Gossip Girl,” “Grey’s Anatomy,” “Mad Men” and more. The experience of selecting “cutting-edge” songs for “The O.C.” stands out to her, though, because so many of the songs were written into the script.


Lead singer Brandon Flowers of the Killers crowd-surfs at a 2006 concert at the Theater at Madison Square Garden. (Scott Gries/Getty Images)

Phantom Planet’s Alex Greenwald performs at a 2004 in-store appearance at New York City’s Virgin Megastore. (Peter Kramer/Getty Images)

Take Rooney, a band named after the principal in “Ferris Bueller’s Day Off” and the first to ever make a guest appearance on the show. They were a favorite of Schwartz’s, Patsavas says, and Marissa even asks Ryan in the second episode if he has heard of the band. Thirteen episodes later, the crew attends a Rooney concert, where Marissa’s shady friend Oliver Trask (Taylor Handley) seems to be friends with the musicians. (This is later revealed to be a delusion after his shadiness escalates to straight villainy. Naturally.)

“They just seemed quintessentially indie and also quintessentially Southern California,” Patsavas says.

The email listed on Rooney’s website now bounces back — RIP — but directly after the appearance, the band reportedly experienced a 200 percent increase in sales. Other, still-active bands used appearances at the Bait Shop, a fictional Newport Beach club the characters frequented, to publicize their music. The Killers, for instance, showed up in the second season to perform “Mr. Brightside” approximately a year after the song had been released, but two months before it climbed the music charts.

“We got to have a candy shop and fill it with all the candy we wanted to eat,” Schwartz says. That candy includes Modest Mouse, the Walkmen and, memorably, Death Cab for Cutie.

Seth incessantly name-checks Death Cab, one instance of which occurs in a tense car ride with his future girlfriend, Summer Roberts (Rachel Bilson). Even after he warns her not to insult the group, she refers to their music as “one guitar and a whole lot of complaining.”

Where Seth failed with Summer, he succeeded with the loyal fan base of “The O.C.” A Willamette Week writer credited the character in 2004 with ushering in Death Cab’s transition from “the property of indie-rock insiders” to a future mainstream favorite: “The potential is there for a mass teen culture revolution, the likes of which we haven’t seen since Kurt Cobain made it hip for boys to wear dresses. For the first time since the grunge years, wimpy dudes have got a big-time role model, a soundtrack and some serious cred.”

The band picked up on this, too. Death Cab performed songs off “Transatlanticism” at the Bait Shop in the second season, soon after it was signed to Atlantic Records.

Much of the success probably came down to timing, according to Schwartz. MTV had fallen out of favor, and Napster had “imploded” soon before. Indie artists were more willing than ever to “sell out” by putting their music on a teen soap opera.

“There was a hunger for the audience to discover new music, but there wasn’t any tool for the audience to discover new music,” Schwartz says. “Our show filled that void.”

Death Cab’s record sales jumped after the band appeared on the show, Schwartz adds, and the “O.C.” team suddenly found itself in a place where groups as famous as the Beastie Boys asked to be featured. There was an entire episode that only used Beck songs, and Capitol Records even reached out at one point to see if Schwartz and company would pick a song to use off Coldplay’s new album “X&Y.” (They went with “Fix You,” which plays in Season 2’s penultimate episode as Seth and Summer reunite at the prom while, separately, his grandfather has a heart attack.)

Mmm? Whatcha say? Oh, yes. It’s definitely time to talk about Imogen Heap.

The team wanted to use Heap’s “Hide and Seek” for the show but didn’t know when, so Patsavas used their newfound power to reserve it for some point in Season 2. The perfect moment arrived in the finale, after Seth reveals that Ryan’s brother Trey (Logan Marshall-Green) assaulted Marissa. As the Atwoods fight in Trey’s apartment, Marissa somehow gets ahold of Trey’s gun and pulls the trigger.

The song kicks in, and blood slowly trickles out of Trey’s mouth as Heap’s synth voice sings, Mmm, whatcha say? Mmm, that you only meant well? Well, of course you did.

Melodramatic moments like this practically set themselves up to be parodied, which, of course, this one was — two years later. “Saturday Night Live” paid homage to the admirable ridiculousness of the scene with “Dear Sister,” a largely slow-motion digital short — in which Bill Hader, Andy Samberg, Shia LaBeouf and Kristen Wiig all get shot right before police officers Fred Armisen and Jason Sudeikis do the same to each other — that led to an entire genre of “Mmm, whatcha say” humor.

For what it’s worth, Schwartz and Savage love the jokes. They speak to the soundtrack’s lasting influence, after all.

“As they say, parody is the sincerest form of flattery,” Schwartz says. Then, before Savage can tell him otherwise, he clarifies, “That’s not what they say. But it’s true.”