Conversation so far:
How did the group Girls' Generation form?
How many singers were there in Girls' Generation when they formed?
Originally a nine-piece group, Jessica Jung departed from Girls' Generation in September 2014.
What was Girls' Generation's first project after formation?
In July 2007, Girls' Generation had their first stage performance on Mnet's School of Rock, where the group performed their first single, Into the New World.
How did Girls' Generation's performance of Into the New World on Mnet's School of Rock go?

Question: Was that their debut?
Self-contained rewrite: Was Girls' Generation's performance of Into the New World on Mnet's School of Rock their debut?