Conversation so far:
What is Antennas to hell?
second album at Sound City.
How popular was this album?
Around this time, conflicts arose between band members due to extensive touring and recording schedules.
When was Antennas to Hell released?
CANNOTANSWER.
What was Knotfest?
first annual music festival.
When did that take place?
August 17, 2012.
Where was the location for the festival?
Mid-America Motorplex near Pacific Junction, Iowa.

Question: Did any other musicians play at the festival?
Self-contained rewrite: Did any other musicians play at Knotfest besides Slipknot?