LOS ANGELES – There was a time around 1997 when no matter where you were – in the car, on the StairMaster, at the dentist’s office – you couldn’t help but hear “My Heart Will Go On,” the soaring Celine Dion ballad from “Titanic.”

Resistance was futile. It did go on, and on, and on – an example not just of great marketing, but of the kind of movie theme song that no longer exists.

These extinct songs were big and poignant on their own, but also used skillfully within their films. They became “a souvenir” of the theatrical experience, as six-time Oscar-nominated songwriter Diane Warren puts it.

For decades, theme songs like “Evergreen” or “Arthur’s Theme” or “(I’ve Had) The Time of My Life” were huge radio hits, often peaking at No. 1 on the pop chart and going on to win the Academy Award for best original song. (All the tunes mentioned so far have received the honor; the list of winners throughout the 1970s, ’80s and ’90s is staggering.)

But in the past few years, filmmakers like Cameron Crowe and Wes Anderson (following the example set by directors like Martin Scorsese) have been more likely to choose pre-existing songs to punctuate a moment or create a certain mood. Then those soundtracks – like the ones for Crowe’s “Vanilla Sky,” Anderson’s “Rushmore” or Zach Braff’s “Garden State” – go on to be popular themselves.

It seems there’s just no room on the pop charts any more for an “Up Where We Belong” (from “An Officer and a Gentleman”) or a “Take My Breath Away” (from “Top Gun”). Eminem’s “Lose Yourself” rap from the 2002 film “8 Mile” is the rare recent Oscar winner that’s also had radio success – as catchy as “It’s Hard Out Here for a Pimp” was from 2005’s “Hustle & Flow,” it wasn’t exactly radio-friendly.

What made those songs work, Warren said, is that “they’re hit songs, first and foremost. They fit the movie and they exist outside the movie.

“‘I Don’t Want to Miss a Thing,'” which earned Warren an Oscar nomination, “was a hit song,” she says. “It helps that it was with ‘Armageddon’ and it was used really well, but I think Aerosmith would have had a hit with that song (anyway).”

So where did those original tunes go?

Jesse Harris, the Grammy-winning songwriter of Norah Jones’ hit “Don’t Know Why,” who also wrote the music for Ethan Hawke’s “The Hottest State,” thinks filmmakers just don’t bother to seek them out anymore.

“What movies used to do,” he said, is “create a nostalgia that was specific to the film itself, and the only way to do that is to use original music.”

Of course, radio has changed vastly and become more genre-specific over the past decade, which hurts enormous movie songs with intended mass appeal, said Kid Kelly, a DJ on Sirius satellite radio’s top-40 channel Hits 1. He points out that adult contemporary stations, where many of these movie themes traditionally have been popular, can be broken down even further to “hot,” “urban” and “soft” subgroups.

“There’s so much fragmentation out there, it’s hard to find the right song,” he said. “So my guess is that they just stopped looking.”

Singer-songwriter Sondre Lerche, whose music appears in the Steve Carell comedy “Dan in Real Life,” thinks tastes have changed irrevocably from the 1970s and ’80s.

“It was a different time for songwriters. I started thinking immediately about that Burt Bacharach song from ‘Arthur,'” Lerche said. “It’s impossible today with the music climate, trends, styles, to imagine a songwriter like Burt Bacharach or his equal today writing a song like that. It’s just so unfashionable in a way. It would be perhaps a great song and a great moment in a film, but it would never be a huge hit. It would never have a pop-culture impact, it wouldn’t be played on commercial radio.”

“I don’t know,” he added. “Maybe if 50 Cent did the theme for some big romantic comedy.”

There have been movies this year whose original songs have enjoyed some external success, if not become huge hits, including Eddie Vedder’s “Hard Sun” from “Into the Wild” and the soundtrack to the indie musical “Once” by Glen Hansard and Marketa Irglova.

Kirsten Sheridan, daughter of veteran Irish filmmaker Jim Sheridan, who’s directing her first studio film with the musical “August Rush,” considered using songs from Hansard’s band The Frames, but made “a really important decision” to go with original music. The movie, which opens Nov. 21, follows the elusive connection between the lead singer of a rock band (Jonathan Rhys Meyers), a classically trained cellist (Keri Russell) and their long-lost son (Freddie Highmore), who tries to reunite the family through song.

“We had three music supervisors hunting down three original songs for Jonny Rhys Meyers’ band to perform and for Jonny to sing,” Sheridan said. “I didn’t want connotations, for people to have an idea in their heads, if they’ve heard them in other movies or had other preconceptions with pre-existing material. We felt it was really important for the film to feel real, for it to feel like a real band.”

John Sayles also wanted original music for “Honeydripper” (opening Dec. 28), about rival juke joints in 1950 Alabama, rather than choose blues or R&B; songs people already knew. Sayles co-wrote several of the tunes, something he’s done for previous films including “Limbo” and “Sunshine State.”

“Here with the genre we’re in, we can tailor something more specifically by writing in that genre than we can finding something to fit that moment,” he said.

Plus it’s more cost-efficient, the longtime independent filmmaker added: “The film rights for music have shot way up from when I began. The larger publishing companies have bought out the smaller ones so you can’t find bargains anymore … It’s rare to get a song for less than $5,000. If it’s a Beatles song, it can be hundreds of thousands.”

Besides, picking that perfect pop song isn’t as easy as it might sound, says Crowe, who has created iconic music moments in such movies as “Say Anything …” and “Almost Famous.” “You have to live and breathe it,” he said. “You try to create that marriage and so often the record can overwhelm or be more eloquent than the movie.”

The famous scene in “Say Anything … ,” in which John Cusack holds a stereo above his head outside Ione Skye’s window and blares Peter Gabriel’s “In Your Eyes,” almost featured a different tune.

“That needed to be the perfect song. We even brought in a songwriter, a la Bacharach, to come in and write for that moment, and that really didn’t work,” he said in an interview. “Nothing worked but that song. It was written in the script to be a Billy Idol song, ‘To Be a Lover.’ It was the week that I liked that song.”

But then when it came time to film that scene, he realized the upbeat Idol tune wouldn’t work. (“Cusack wanted Fishbone – ‘I wanna play Fishbone!'” Crowe added, saying that the actor is actually playing that band’s “Party at Ground Zero” while shooting this wistful moment.)

“We tried every possible song. Then I was driving to the editing room one day and I had the wedding mix from my wedding in my car. I was listening to stuff on it, it brought back memories, then ‘In Your Eyes’ comes on. ‘I drive off in my car!'” he gushed, quoting Gabriel’s lyrics. “It’s a song about instincts! I put the pedal to the floor and we put it in the scene and it worked. Then we had to try to get the song, which is its own crusade and a really difficult thing.”

Charles Bernstein, chairman of the executive committee of the academy’s music branch – whose members vote for the best original song Oscar – points to 1969’s “Easy Rider” as the turning point, with its soundtrack that famously included Steppenwolf’s “Born to Be Wild” and The Band’s “The Weight.”

“That was the first time a soundtrack album became an entity in and of itself – a bunch of existing hits used to score an entire film,” said Bernstein, who has composed scores for more than 100 movies. “Ever since then, there’s been a split in the film community. There’s ‘The Way We Were,’ ‘Love Is a Many-Splendored Thing’ tradition, then there’s the ‘Easy Rider’ tradition of getting a bunch of recognizable, youth-oriented songs from whatever era it is.

“What is really difficult, and why we give Oscars for it, is coming in and becoming a part of the filmmaking process – creating from zero, creating from a blank page, magic,” he added. “Naturally, a lot of people are prone to take the easier road.”