I suppose brass, but also a little bit of a crystal-like sound, keeping the track upbeat, but also soothing. It could also be described as a type of out at night, hitting the city music, but keeping it more castle-oriented. also, any drum-work could help out, too. If it can be kept simple, go for it. However, If things need to get complicated, I more than understand, I had that problem on an essay once [I know it doesn't relate well but I'm thinking general art instead of music] and had to get bow-legged tying everything together properly.