If you do one festival this year, do the Andong Mask Dance Festival.
Here's more information about the festival.
The Official Website
And some (pretty rough) videos from my 2008 and 2009 trips:
The Must-See Fireworks: (read about them at my original andong blog write-up)
The (UNESCO World Heritage site) folk village where some of the festival happens:
Hopefully the music is better than in 2008...
My boy Evan: