As they sing, the video cuts between footage of the pair walking down the "long, lonesome road" and the encounter with the demon played by Dave Grohl. The demon also performs the electric guitar solo in the music video. After the solo, Black and Gass jump out of the booth and start shouting the lyrics at mall shoppers and dancing flamboyantly. Passersby include cameos from Lynch and Ben Stiller. While most pay no attention, an old lady, played by Linda Porter assaults Black with her purse after he grabs her while singing. A policeman, played by JR Reed, who played "Lee" in the band's television series, takes Black and Gass away. At the end the same old lady who was frightened by the duo picks up the now-recorded CD, eyes glowing red, and cackles demonically.

Answer this question based on the passage: who plays the devil in tenacious d tribute? Okie... think carefully first, then make a decision:
The relevant information is: As they sing, the video cuts between footage of the pair walking down the "long, lonesome road" and the encounter with the demon played by Dave Grohl. So, the answer is Dave Grohl.