Identify the sentence type. he never smiled, he never frowned, he never changed his voice from the gentle-flowing key to which he turned the initial sentence.

The sentence most likely used parallelism. Parallelism is the use of the components in a sentence that are the same grammatically or similar in construction, sound or meaning. It is used as a literary device in may works. Examples are "James ran into the garden, into the room and into our hearts.", "Like father, like son.", and "Easy come, easy go."