Dear Sir/Madam
It has come to my knowledge that your previous stage manager has resigned the job recently, and as the show must go on, I believe you may be looking for someone to fill your stage manager role. I would like to put forward my own case for the job.
I have been interested in theater since school as it allows me to combine my passion with my penchant for pragmatism. In fact, I have been managing the stage over the last five years for (name of theatre company). I am accomplished to manage stage for both low-budget productions and high-tech extravaganzas. I have also worked as manager for productions with both amateur crews and unionized crews. Moreover, I have managed the shows well on on or under budget.
Although I enjoy my current job, I am looking for a new challenge. I am also enclosing my resume for your review. I shall call you in a few days to discuss the possibility of my joining your theater group as stage manager.
Sincerely