*"It's Raining Men" by The Weather Girls was written for Donna Summer who declined it because she was a born-again Christian and the lyrics were too suggestive. It was offered to Cher, Barbra Streisand, and Diana Ross who all declined it.
*Whitney Houston's "How Will I Know" was originally written for Janet Jackson who declined it because she thought it was too weak for her sound at the time. ~tbh, I agree. Whitney's vocals elevate the song a lot and it just wouldn't slap the same with Janet~
*The Neptunes wrote "I'm a Slave 4 U" and "Boys" for Janet Jackson who declined them because she thought they were too sultry for her vocals. They were then passed to Britney Spears who was looking for a more mature sound for her 3rd album.
*Watch the vid for the rest!