The little girl sang the whole song in a high-pitched voice.

high-pitched 是由形容词 high（高的）和名词 pitch（音高）加上后缀 -ed 组成的复合形容词。pitch 在音乐中特指"音高"，high pitch 指"高音调"。 high-pitched 字面意思是"具有高音调的"，引申为"声音尖细的"，常用来形容儿童或女性较高的嗓音。