Bradley Cooper and Will Arnett are to star in 'Is This Thing On?'.

Bradley Cooper and Will Arnett are to lead the cast of Is This Thing On?

Bradley Cooper and Will Arnett are to lead the cast of Is This Thing On?

The 48-year-old star will also direct Arnett in the forthcoming film, and he will produce the Searchlight motion picture through his Lea Pictures banner.

According to Deadline, the movie is in early development and Arnett has written a draft script with Mark Chappell before the Writers Guild of America (WGA) strike began.

Cooper is also expected to join forces with Arnett and Chappell on the next version of the script, but that won't be until the strike ends.

Plot details for the movie are being kept under wraps.

One of Cooper's upcoming roles will see him star as acclaimed conductor Leonard Bernstein in biopic 'Maestro'.

Cooper recently described it as the "most terrifying" film of his career.

In a Focus Features roundtable with 'Tar' star Cate Blanchett and director Todd Field, Cooper said: "Having worked on a project in the same world (as 'Tar'), the level of respect that I have for that world and that podium, it is the most terrifying thing I've ever experienced.

"And it's so odd because so many people - I don't know if you've come across this - but people that I have met in the last five years have said, 'Well, what is it that conductors even do? Aren't you up there sort of doing like this?' "

Cooper - who is also directing the Bernstein biopic - added: "And my answer is, 'It's the absolute hardest thing you could ever want to do. It is impossible.' "

The 'A Star Is Born' actor had high praise for Blanchett and Field for making conducting look easy in 'Tar'.

He said: "Not only did you make the conducting look easy, but the rehearsal. The rhythm of the rehearsal and the way you wrote and filmed it was just so appetising on every level as a viewer. It was truly mind-blowing... There's no one else who could ever play that role (of Lydia Tar)."