I had some speech therapy before that taught me that constantly changing my pitch in a singsong manner (high - medium - high - medium) was an effective way to reduce stuttering. It’s not singing but it’s kinda like it? That said, I decided not to do it all the time because it sounds ridiculous and I could get by because my case is somewhat mild. Also it takes a fair bit of concentration to do. But in school I would use that technique during presentations to make it sound like I was emphasising key points. It was pretty helpful.