It’s no secret that there’s a ton of money in the music industry. In fact, two musicians (Jay-Z and Diddy) recently made it onto the Forbes Top 10 Wealthiest Celebrities list.

It takes a lot of hard work (and luck) to get even close to that kind of success, though. And just like with any profession, most musicians spend years paying their dues and working their way up before they finally get noticed. And for many musicians, “paying their dues” means letting other people take credit for their work by being ghostwriters.

Yes, even musicians use ghostwriters!

While it is a fairly well-known fact that a lot of famous musicians don’t actually write their own songs, it may surprise you how many of those songs are actually written by other (sometimes equally well-known) musicians.

Take Kelly Clarkson’s massive hit, “Miss Independent,” for example. It was actually written by none other than the insanely talented Christina Aguilera.

And before Bruno Mars became a household name, he was ghostwriting hits for CeeLo Green and Flo Rida, among others.

In fact, some of the most well-known songs of all time were actually written by ghostwriters and not the artists who made them famous. While on my quest to find ghostwritten songs, I came across quite a few big surprises. For example:

• Aretha Franklin’s “Respect” was actually written by the famously soulful R&B artist, Otis Redding.
• While the hit “Nothing Compares 2 U” conjures up memories of Sinead O’Connor’s heart-wrenching rendition, it was actually written by one of the most recognizable and talented artists of all time: Prince!
• The 1966 No. 1 hit “I’m a Believer,” made famous by The Monkees, was written for the band by Neil Diamond.
• Justin Bieber’s well-known “Love Yourself” was written by another very famous artist: Ed Sheeran.
• “Whataya Want From Me?”, which is arguably the most popular song from artist Adam Lambert, was actually written by Pink.
• “Halo” may be one of Beyoncé’s most famous songs, but it was actually written by Ryan Tedder, lead singer of the band OneRepublic.
• “It’s Raining Men” made famous by The Weather Girls was surprisingly written by Paul Shaffer, musical director of David Letterman’s late-night shows, with Paul Jabara, who wrote “Last Dance” for Donna Summer.

Big hit songs are not the only things that are ghostwritten by musicians, though. Before they got their big break, several well-known musicians got their start by ghostwriting advertising jingles.

I would be shocked to find a person who is not familiar with State Farm’s “Like a Good Neighbor” jingle, or the catchy “Stuck on Band-Aid” tune. But, did you know that they were both written by Barry Manilow? Manilow’s jingle portfolio also includes tunes for Pepsi, Kentucky Fried Chicken, and Stridex, among others.

Barry Manilow is not the only mega-musician to write commercial songs, though.

It’s a pretty fair statement to say that basketball fans everywhere would recognize the tune of “Roundball Rock,” also known as the “NBA on NBC Theme.” But who would have guessed that the song was written by the soft-pop overlord, John Tesh?

And although Randy Newman may not be a well-known name, his Pixar contribution of “You’ve Got a Friend in Me” from Toy Story is sure to ring a bell. A little-known fact about Newman, though, is that he also wrote Dr. Pepper’s “Most Original Soft Drink Ever” jingle.