If the wires are currenty loose -- and the reason for your wind instrument not working is a result of some chafe ;^)? You should be able to "see" the wires from a halyard hole, or the top of the mast, or...

If they are loose now -- then you could simply use the existing wire as a guide. If you want to do it "right" then there are bunch of solutions, but I think that is best done (as Larry suggested) on the ground vs. in the air. "Right" may not be necessary, depending on what you have going on. Usually, if you don't have a lot of halyard action, unless you "cross" a wire, you really probably can get by with a simple direct "drop" -- but if you try to replace a halyard later, you need to be careful not to "drop" it so as to cross the wire.

There are some fabric conduits (like a sleave) that protect the wires against chafe. Sometimes conduit is used, sometimes there are dividers in the mast which provide a guide.