Conversation so far:
What was Dreamgirls' (film) premier date?
Dreamgirls debuted in four special road show engagements starting on December 15, 2006, before its nationwide release on December 25, 2006.
Did all of the stars of Dreamgirls attend?
Did anything of interest happen at the Dreamgirls premier?

Question: What was the road show?
Self-contained rewrite: What was the road show?