Joining the blues act in the latest additions to the lineup, that will be officially announced Wednesday, are Bassnectar, Silversun Pickups, Fitz and the Tantrums, Polica, The Knocks, Moon Taxi and Turf War.
The festival is set for July 20-22 and will feature headliners The Killers, The Black Keys and Jack White, along with other artists such as Death Cab for Cutie, John Legend, Lupe Fiasco and The Flaming Lips.
These may not be the final acts added to the event.
"That's unclear at this time. We are still exploring opportunities," said Firefly spokeswoman Meghan Roman.
Advance three-day passes are currently on sale for $198 and will rise to $218 once they are sold out. Camping opportunities are also available.
For more information and to purchase tickets, visit the website.