Conversation so far:
What was the reasoning behind returning to guitar oriented sound?
CANNOTANSWER.
Did this affect album sales?
CANNOTANSWER.
Why did they go on hiatus?
1997.
Was there a reason behind the hiatus?
due to personal tragedies in Peart's life.

Question: What happened to Peart?
Self-contained rewrite: What happened to Peart?