I believe this case would benefit largely from teacher preparation. It is my first thought. The teachers know and understand the child's daily behaviors. Does the child frequently howl out during that specific time or activity? It was stated that during music time, specifically, that the child howls. Is the music enthusing her? Is that the way the child actively participates in the activity? Is that her way of singing? If so, the teacher can prepare for that situation. The teachers could practice modeling the appropriate ways to participate in music time by participating and reminding the child not to howl each time. Is the child howling due to irritation over overstimulance from the music? I have a personal experience to share that could also benefit the situation.