The sentence suggests that the singer’s voice was unpleasant or jarring to the pianist’s ears. However, without further context, it’s difficult to determine the reason for the pianist’s reaction. It could be that the singer was inexperienced or had a poor technique, or perhaps she was intentionally singing off-key or in a dissonant style as part of a musical performance. It’s also possible that the pianist simply had personal preferences or biases regarding vocal styles. Overall, the sentence conveys a negative reaction from the pianist towards the singer’s singing.