We've all been there: you're minding your own business having a jam session and a song that you love comes on! You're excited and anticipating the lyrics or the melody so you can sing along, when - wait, that's not this song? I could've sworn that it started just like that. This happens way more often than you think and no, you're not losing your mind. It's actually quite common for songs to use similar or even the exact same melodies or beats. While some artists get legal permission to sample a song written and recorded by another artist, others just use slightly varied versions. This isn't to say that all artists in this list intentionally copied another artist, but it does make you question the originality of some of your favorite artists.

1. "Closer" - The Chainsmokers ft. Halsey vs. "679" - Fetty Wap ft. Remy Boys

"Closer" was released in 2016 and "679" was released in 2015. They feature a similar melody and beat.

2. "Cheap Thrills" - Sia ft. Sean Paul vs. "Africa" - Toto

Unfortunately, I couldn't find a mash up of these two! Their choruses are quite similar. "Cheap Thrills" was released in 2016 and "Africa" was released in 1982.

3. "Send My Love (To Your New Lover)" - Adele vs. "Royals" - Lorde

These two songs are in the same key and have very vocal harmonies that are quite alike. "Send My Love (To Your New Lover)" was released on May 16, 2016 and "Royals" was released on June 3, 2013.

4. "Thinking Out Loud" - Ed Sheeran vs. "Let's Get It On" - Marvin Gaye

These two have the same beat and tempo, as well as something else I can only describe as "groove." Ed Sheeran released "Thinking Out Loud" on September 24, 2014 and Marvin Gaye released "Let's Get It On" on June 15, 1973.

5. "Cancer" - My Chemical Romance vs. "Bad Things" - Machine Gun Kelly ft. Camila Cabello vs. "Look What You've Done" - Jet

Again, I couldn't find a mash up for these three, but I think their melodic resemblance is pretty clear. "Cancer" was released in 2006, "Bad Things" was released in 2016, and "Look What You've Done" was released in 2003.

6. "Social Casualty" - 5 Seconds of Summer vs. "Sugar, We're Goin' Down" - Fall Out Boy vs. "This Is Gospel" - Panic! At the Disco

Battle of the Pop Punk Bands! All three of these songs are in the key of D Major and feature similar chord progression, melodies, and beats. "Social Casualty" was released in 2014, "Sugar, We're Goin' Down" was released in 2005, "This is Gospel" was released in 2013.

7. "Cake By the Ocean" - DNCE vs. "UpTown Funk!" - Mark Ronson ft. Bruno Mars

That's right, some of your favorite summer songs are quite alike! With similar beats and a nearly identical bass line, these two songs were made for success. "Cake By the Ocean" was released in 2015, while "UpTown Funk!" was released in 2014.

8. "Prayer in C (Robin Schulz Remix)" - Lilly Wood & The Prick and Robin Schulz vs. "Sugar" - Robin Schulz ft. Francesco Yates

I couldn't find a mashup for these two, but their intros and main riffs parallel even if they aren't in the same key. They also have the same producer, Robin Schulz. "Prayer in C (Robin Schulz Remix)" was re-released (the original song was released in 2010) in 2014 and "Sugar" was released in 2015.

9. "Dear Future Husband" - Meghan Trainor vs. "Dance With Me Tonight" - Olly Murs vs. "Runaround Sue" - Dion

This is the same song! Meghan Trainor's "Dear Future Husband" and Dion's "Runaround Sue" even feature the same a capella opening! "Dear Future Husband" was written in Db Major, making it a half step lower than the other two, but it goes on to a key change into - you guessed it - D Major, just like Dion and Ollys' songs! Although it's clear who came up with the melody since "Runaround Sue" was released in 1961, followed by "Dance With Me Tonight" in 2011, and finally "Dear Future Husband" in 2015.

10. "Hella Good" - No Doubt vs. "Billie Jean" - Michael Jackson

These two inspired this whole article! With Spotify on shuffle as I got ready, a familiar beat started playing only for me to realize it wasn't the song I thought it was! It's interesting to note the similar bass lines, as well. "Billie Jean" was released in 1982 and "Hella Good" was released 20 years later in 2002.

11. "Stitches" - Shawn Mendes vs. "Treat You Better" - Shawn Mendes

Both of Shawn Mendes' songs are both in the key of Bb Minor and feature co-writer Teddy Geiger. Maybe they sound so alike because they're about the same girl? Maybe Shawn just likes Bb Minor? I can't say. "Stitches" was released on May 5, 2015 and "Treat You Better" was released on June 3, 2016.

12. "Never Gonna Leave This Bed" - Maroon 5 vs. "Starlight" - Muse

There isn't a mash up for this pair, but the choruses resemble each other quite a bit. They aren't in the same key, but in the relative keys of G# Minor and B Major. Muse released "Starlight" in 2006 and Maroon 5 released "Never Gonna Leave this Bed" in 2010.

13. "Best Song Ever" - One Direction vs. "Baba O'Riley" - The Who

I don't have a mash up for these two, but the intros are nearly identical. Pete Townsend of The Who told Rolling Stone:

"... I like the single. I like One Direction...The chords I used and the chords they used are the same three chords we've all been using in basic pop music since Buddy Holly, Eddie Cochran and Chuck Berry made it clear that fancy chords don't mean great music – not always. I'm still writing songs that sound like 'Baba O'Riley' – or I'm trying to!"

The Who released "Baba O'Riley" in 1971, while One Direction released "Best Song Ever" in 2013.

14. "Knee Socks" - Arctic Monkeys vs. "Gorgeous" - Kanye West ft. Kid Cudi and Raekwon

No mash up here, but the main riff throughout both songs are only slightly different. Kanye released "Gorgeous" in 2010, before the Arctic Monkeys released "Knee Socks" in 2013.

15. "This Is What You Came For" - Calvin Harris ft. Rihanna vs. "East of Eden" - Zella Day

Although these two have slightly different keys, the tempo, melody, and genres are the same! "This Is What You Came For" was released in 2016, while "East of Eden" was released in 2014.