Question about music teacher

My daughter with apraxia is in the 2nd grade at school, where she is doing well with the exception of music class. Last week after school she was crying because her music teacher yelled at her in class for not singing fast enough! I am very upset by this and not sure how to handle it. My daughter is on an IEP at school and the music teacher is aware of her diagnois, because I told her about it at the beginning of the year. My daughter is not physically able to sing fast - I mean really would the teacher yell at a visually impaired student for not being able to read the music? I am just wondering how to handle this??