Spotify users have an endless library of tunes and sounds to listen to, but that doesn't make all of it things you actually want to hear.

Deep in the heart of the music streaming service, past the Justin Bieber albums and Rihanna singles, lurks the tracks you might have not known existed. The ones that make you scratch your head and say "WTF?"

SEE ALSO: The 100 Most Beautiful Songs in the World, According to Reddit

If you want the whole playlist, we've collected all of the strangest finds here.

(Pro tip: You might want to make sure you're in private mode on some of these.)

1. "When You Were Young" - Never Mind the Pan Pipes

All of the indie hits with pan pipes on vocals.

2. "It's Raining Men" - Arnold Scwarzenegger's Total Body Workout

Arnold is going to "PUMP YOU UP!" to the tune of "It's Raining Men," among other classic songs.

3. "Carl Calling You Ringtone" - Your Name Ringtone

Not sure how you actually use these as real ringtones, unless you just record it from your phone. Bonus points if you use this one and your name isn't even Carl.

4. "Rap-A-Yodel" - The Rapping Cowboy

Yodel remix.

5. "Snoopycat" - Marian Anderson

Anderson was a talented famous opera singer and civil rights activist. She also really liked her cat, Snoopy.

6. "Learn Japanese" - Subliminal Messages

Sure, it sounds like a rainy day in the forest, but when you "unlock the floodgates of your subconscious mind," you might find yourself speaking Japanese.

7. "Prokofiev: Peter and the Wolf/Beintus: Wolf Tracks" - Bill Clinton

The former U.S. president won a Grammy, but not for his saxophone playing. It was for speaking in this musical fairy tale.

8. "Gangsters Paradies" - Hits von Kids

Have you ever wondered what a Coolio rap would sound like when it's performed by the German version of Kidz Bop? If that piqued your interest, there's also a pretty swell cover of "Cotton Eye Joe."

9. "Who Let the Dogs Out" - Rudolph the Rednosed Reindeer

Not really what you'd expect from Rudolph.

10. "Lucy in the Sky With Diamonds" - Wing

One thing I can definitely say about this is that it is a cover of a Beatles song.

11. "Tweet Ya Later Poke Ya Now" - My Space On Facebook

I'd prefer you did neither.

12. "Cheeseburger in Paradise" - University of Washington Husky Marching Band

You probably never realized you wanted to hear a marching band perform a Jimmy Buffet song. That's ok, because there are multiple songs to choose from.

13. "Bohemian Rhapsody" - William Shatner

It's as strange as you think it is.

14. "Bring Me to Life" - The Buddha Lounge Ensemble

This group provides all of the zen versions of alternative and rock songs that you were never looking for.

15. "Dogs Singing the Hey Song" - The Barking Dogs

16. "Celebration Donut Spin Out" - NASCAR Sounds

17. "56K - Rap" - Richard Jenkees

This one goes out to all of my Internet friends.

18. "I'm the Greatest (Ali's Bicentennial Freedom Song)" - Muhammad Ali

When Ali wasn't knocking competitors out in the ring or inspiring crowds with his words, he was singing about how awesome he was.

19. "Female and Her Pup Being Reunited" - Kerguelen Fur Seal

I know, I know — you've been wondering what that sounded like. Us too. (FYI, that's just one of millions of random sound effects.)

20. "Breast Enlargement" - Subliminal Message Therapy Ocean Music

Don't worry, fellas, there's one for you too.

Image courtesy of Flickr, caribb