Jay-Z has defended the controversial move of trademarking his daughter Blue Ivy's name. The musical couple had their daughter in January 2012 and, speaking in a new interview with Vanity Fair, Jay Z opens up about Blue Ivy's musical preferences, as well as why he chose to trademark her name shortly after the birth. The rapper says he trademarked 'Blue Ivy' in order to stop others profiting from his family. "People wanted to make products based on our child's name and you don't want anybody trying to benefit off your baby's name," he says. "It wasn't for us to do anything; as you see, we haven't done anything." Jay Z also claimed that his daughter Blue Ivy prefers his music to her mother, Beyonce's. "She does like her mother's music - she watches Beyoncé's concerts on the computer every night. But my album came out and I don't know if Blue ever heard any of my music prior to this album - she's only 18 months old and I don't play my music around the house. But this album was new, so we played it. And she loves all the songs," he says. Continuing, Jay Z adds: "She plays a song and she goes, 'More, Daddy, more. Daddy song.' She's my biggest fan. If no one bought 'Magna Carta', the fact that she loves it so much, it gives me the greatest joy. And that's not like a cliché. I'm really serious. Just to see her – 'Daddy song, more, Daddy.' She's genuine, she's honest, because she doesn't know it makes me happy. She just wants to hear it."