Same reasons as for my annealing post: I'm trying to do a nicer job of mounting wheels on model airplanes.
Given a piece of music wire that's already bent up (because you don't really know where the end is going to be until it's bent), how would you put a snap ring groove in a piece of hardened music wire? Would a groove made by a 1/32" cutoff disk in a Dremel tool have any chance of being good enough? Can you think of any simple fixturing that would make the process better?