Reilly, who previously has starred in "Chicago," "The Good Girl" and "Talladega Nights," plays the titular singer in the fictional bio-pic "Walk Hard: The Dewey Cox Story."
To promote his new comedy during a writers' strike that has shut down most major TV talk shows, the actor has been performing at post-screening gigs in several cities.
"The tour is going really good," Reilly told UPI in New York Monday.
"We did a show in Los Angeles last week and the Knitting Factory (in New York) is the finale Wednesday," he said. "It's a lot of fun. It beats just your basic Q&A. In terms of getting to interact with the fans of a movie. It's one thing to introduce a screening and say, 'Hey, thanks for coming.' And then it's another thing to take the entire audience from the screening, bring them to a music club and perform all the music from the movie. It's ridiculous fun."