Conversation so far:
What is mindcrime?
In 1988, Queensryche released Operation: Mindcrime, a narrative concept album that proved a massive critical and commercial success.
Was this a successful album?
The album gained critical acclaim and achieved gold status.

Question: Can you tell me a little about the Empire and mainstream success?
Self-contained rewrite: Can you tell me a little about the Queensryche's Empire and mainstream success?