Earlier quoted context omitted.
What if the stress level affects the dopamine level and that affects the stutter? I have a stutter too and this was a very interesting article to add to my "head-canon" on why people stutter. My stutter is also affected by moods. Maybe we're living -- or rather, speaking -- on the edge of the brain-body connection.
I had a roommate with a stutter, but never when telling a joke, talking to the dog, or singing. We are way more complicated than we understand!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2996848/
> As illustrated in this paper, singing represents a promising therapeutic tool in a variety of neurological disorders. Singing is particularly useful in ameliorating some of the associated speech-motor difficulties because of features such as continuous voicing, decreased production rate, and increased awareness of individual phonemes. Although the precise mechanisms underlying the efficacy of singing remain largely unexplored, a number of hypotheses have been proposed