Rapper Kanye West may have an infamous ego, but he chills out when it comes to his professor mother, for whom he penned the tribute "Hey Mama." In a letter to his mother in Essence, West wrote, "Everything is in that song – how much I care about you and how you've always been there for me. The first time you heard it, you cried and said it was beautiful." And now? It's her ringtone.