UPDATED: Daniel Richtman says Emily Blunt was added to the cast.
EARLIER: Bradley Cooper’s “Maestro” isn’t even out yet, but the actor/filmmaker has already set up his third feature as a director. Cooper will be teaming up with Will Arnett on the Searchlight-produced “Is This Thing On?” Both are set to co-star in the film with Cooper also directing. Arnett penned the script with Mark Chappell. Plot details are being kept under wraps. Cooper is currently in post-production on the Netflix biopic “Maestro”, which is the follow-up directorial effort to his Oscar-winning “A Star Is Born”.