Also, from personal experience, when you train yourself to use that new “sing song” type of voice....it does work, but only for a very limited amount of time. Then what happens is that style of speaking becomes your new normal voice, and then the stuttering quickly returns. It only lasts as long (or seems to) as you are making that end-run around stuttering. Once it figures out what you’re doing, it begins to use that new route. I know this isn’t a great metaphor for what happens, but it feels like it is.