Conversation so far:
what was extended break?
during Silverchair's hiatus, the pair re-united and formed The Dissociatives.
What year was that?
2003.
What happen in 2004?
Silverchair performed to help raise funds for aid organisations working in disaster affected areas.
What was one of their side projects?
Johns and Mac released an internet-only EP, I Can't Believe It's Not Rock.
What year was that?
In mid-2003, during Silverchair's hiatus, the pair re-united and formed The Dissociatives.
Are there any other interesting aspects about this article?
The duo provided the theme music for the popular ABC-TV music quiz show Spicks and Specks.

Question: What else was they known for?
Self-contained rewrite: What else was Silverchair known for aside from providing the theme music for Spicks and Specks?