If we're not specifically instructed to do something, can we?

My question is spawned from the Church of Christ doctrine. I go to a Church of Christ university and our chapel is fully a Capella. However I've been raised baptist and music was always a part of every service. My school has tried to teach that since we are not instructed to use instruments, we CANNOT use instruments. Although not pastors or anything, I've heard some Church of Christ disciples say that the only instrument God ever made is the human voice. From what I've read around the internet, some say it's tradition , others say that since God hasn't told us we can then we can't (I've heard this called the "null argument"). Personally I believe God is more about "Do Nots" instead of focusing on "Dos" when it comes to how we live our lives. According to this table at Wikipedia , there are 12 important facts conveyed in the 10 commandments (no matter how you group them together). Of those 12 facts, 9 of them are "Do Nots." Am I wrong to believe that if we're not specifically told to do something, it's allowed? I'm not trying to be overly literal, I understand there are blanket statements that do affect many things we are not specifically told not to do.