Conversation so far:
Who was Alvin and the Chipmunks' Simon Seville?
Simon Seville is the tallest and the middle brother of the Chipmunks.
What can you tell me about Alvin and the Chipmunks' Simon Seville?
In addition to having an IQ above that of Einstein, Simon Seville possesses a dry sense of humor and a keen wit.

Question: who did he sing with?
Self-contained rewrite: Who did Alvin and the Chipmunks' Simon Seville sing with?