Play just the first few bars of songs like “My Heart Will Go On” by Celine Dion, “Don’t You (Forget About Me)” by Simple Minds or even “Mad World” covered by Gary Jules for any average moviegoer, and his or her response will be filled with nostalgia and vivid memories of the specific scene or trailer that used those songs. Just thinking about “Eye of the Tiger” or “Stayin’ Alive” directs my mind toward cinematic classics like Rocky III and Saturday Night Fever, and I was born in 1996.

These are perfect examples of iconic “movie songs,” but as of late, it seems as if this phenomenon of songs “defining” a movie has been obliterated. Just the other day, I heard a certain song on the radio, but when I searched that artist’s album on Spotify, the song was not there. I then proceeded to search the song title, and it directed me to none other than the Fifty Shades of Grey sound track. I became interested.

Are these star-studded “movie sound tracks” simply a cross-promotional tactic used by artists to snag hit songs? What happened to those definitive “movie songs”? Does the general public know that their favorite tune was written for an unrealistic and naughty sex fetish film? Here’s a list of the nine best songs you probably didn’t know were from movie sound tracks.

9. Ellie Goulding, “Love Me Like You Do”
The ubiquitous radio hit was penned as the second single from the Fifty Shades of Grey sound track earlier this year, and since then has peaked at No. 3 on the Billboard Hot 100 and holds the UK record as the second most-streamed track in a single week. It’s also pretty safe to say that the song elevated Goulding into pop superstardom. “Love Me Like You Do” joins The Weeknd’s “Earned It” as a song from the Fifty Shades sound track to chart in the Top 5, and both have helped the sound track sell more than one million copies thus far. Still haven’t seen the movie.

8. Rihanna, “Shut Up and Drive”
“Shut Up and Drive” gets lost within the plethora of Rihanna hits during the late 2000s, but many don’t know that it was featured on the Wreck-It Ralph sound track in 2012. Although it didn’t hit No. 1 on the charts like “Umbrella” or “Disturbia,” the quirky and metaphor-ridden song is secretly one of my favoRihts.

7. Bruno Mars, “It Will Rain”
It seems like every single Bruno Mars releases becomes a hit, but “It Will Rain” was sort of the first time we heard him go darker with his lyrics and production. Fitting, as the song was featured on the Twilight Saga: Breaking Dawn – Part 1 sound track in 2011.

6. Charli XCX, “Boom Clap”
After being a mere featured vocal on Iggy Azalea’s massive hit “Fancy,” “Boom Clap” was just what British pop singer Charli XCX needed to launch her right into the mainstream U.S. music scene. That infectious hook, those waves of synths during the verses, the exceptional use of onomatopoeia? “Boom Clap” was tailored for Charli XCX, and many also don’t know that the song was featured on The Fault In Our Stars sound track in 2014.

5. R. Kelly, “I Believe I Can Fly”
The fact that “I Believe I Can Fly” was prominently featured on the 1996 Space Jam movie sound track, and the single's cover is a serious-looking Kelly in the center with a close-up of Michael Jordan’s face to his left and Bugs Bunny to his right, is probably why the song has lent itself to so much parody. I remember kids would constantly sing, “I believe I can fly/ I got shot by the FBI/ All I wanted was a chicken wing” in elementary school. However, the song was ranked No. 406 on Rolling Stone’s “500 Greatest Songs of All Time” list in 2004, peaked at No. 2 on the Billboard Hot 100, and became the R&B singer’s biggest hit ever. Kelly was probably laughing all the way to the bank.

4. Destiny’s Child, “Independent Women, Part 1”
Released as the first single from the 2000 sound track of Charlie’s Angels, “Independent Women, Part 1” by Destiny’s Child was No. 1 on the Billboard Hot 100 for a whopping 11 weeks and was later named the 18th most successful song of the 2000s. I mean, who hasn’t sat in the front seat of his or her car singing lead and had two friends in the back seat singing those iconic “I bought it” background vocals? Anyone?

3. Pharrell Williams, “Happy”
Sometimes a song comes along that quite literally becomes bigger than life, and Pharrell Williams’s “Happy” is definitely one of those. With its carefree mood and perky rhythm, “Happy” is sure to get anyone’s head nodding or foot tapping, but it did way more than that. “Happy” went on to sell 14 million copies in 2014, making it one of the best-selling singles of all time and a monumental moment in pop culture. Oh, and the song was also featured in Despicable Me 2, but who cares about that?

2. Goo Goo Dolls, “Iris”
The Goo Goo Dolls’ timeless hit “Iris” was originally written for the sound track of 1998 movie City of Angels. However, it went on to become the most-played song of that year in all genres and one of the most-learned songs by 14-year-old boys who'd just bought an acoustic guitar to seduce their crush outside their bedroom window.

1. Eminem, “Lose Yourself”
If you haven’t listened to Eminem’s “Lose Yourself” before a workout, who do you think you are? The song is actually from his own film 8 Mile, which is about a young white kid’s struggle to make it in the African-American-dominated rap music scene. It not only won the Academy Award for Best Original Song but also went on to be the defining song of Eminem’s career. [Post-"The Real Slim Shady," anyway — ed.] Just remember those iconic lyrics: “His palms are sweaty…something something..spaghetti….something something...MOM’S SPAGHETTI.”