Your question has deeper question. Is everything Christian? For example, if the owner of a gas station is a Christian, does that make it Christian gas? Using the term Christian to describe something, can't possibly make it good or bad. I mean if a band were just awful musicians, but they were Christians would the music be good or bad? Was Bach a Christian? Is his music good or bad. All things have to be judged by what Paul said, "some things are not edifying." In other words, they don't build us up. Bad Christian music is not going to make us good Christians, but good music from non-Christians is something to think about. Sure the music might be good, but does it tear you away from what you know to be right and true? There's the answer. Sometimes a non-Christian song, can mean the most spiritually. For example, U2's Sunday Bloody Sunday is one. The Eagle's Desperado is another one. Coldplay's The Hardest Part works too. Good luck in the debate. It will never end until we're before Christ in heaven. e_scott