Ark Master is the one who makes sure everything runs smoothly on the Ark website. He moderates the chat room and updates the website. As for his identity, that remains hush hush.
To record with Ark, you will need to go through the audition process. At the moment, audition dates have not been announced.
Alternatively, Ark occasionally runs a contest. All you need is a profile on the official website and to accept the poll agreement listed under "Contests" to enter for a chance to be selected as a nominee for the competition.