No corrode flux won't corrode copper pipe that is used for potable water. It is water soluble, so it gets washed away as soon as the pipe is used. And for whatever reason, the outside of the joint won't ever corrode either even without being cleaned off. I know this because I used to work for a plumber and made a few thousand solder joints with no corrode flux and solid solder.

It is acidic though, so for music wire it should be cleaned off with a solution of baking soda and water. Even on that I wouldn't worry much, but that's what you can do to be sure it's ok.