John Legend

The prison-industrial complex, poverty, and the school system has more effect on a young black male in America than Jay-Z does, by far. And that's not a diss to Jay-Z. The crime rate in the black community was high before hip hop. Rapping about it is just a reflection of the life a lot of people are living.

People like Dick Gregory, Paul Robeson, Harry Belafonte and Nina Simone show me what the definition of an artist is - it isn't just to make art but to speak truth to what's happening, speak beauty into the world, speak love into the world and also... get involved.

Though builders may build, in the main they follow the plans of architects. Teachers teach, but they must have a text. Politicians govern, but only upon the flow of commentary that raises them up or casts them down.

There's great stuff out there, but I prefer doing a TV show, going to work every day with the same people, and a lot of stuff is not being shot in Los Angeles and I don't really want to do that because my loved ones are here.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.