Final answer:
The seniors couldn't start practicing in the playhouse immediately because initial rehearsals involve tablework, where the director and actors discuss the play and develop characters. Technical rehearsals with the full set and props occur much later in the process.
Step-by-step explanation:
The seniors couldn't begin practicing in the playhouse for the very first rehearsal because this stage of a production usually involves tablework. During tablework, the director and the actors sit down to read and discuss the play, sharing their thoughts and interpreting the script. It is a critical time for the director to outline their vision and for actors to begin developing their characters within that framework. This process takes place before moving into the playhouse, where they will have technical rehearsals and integrate all design elements such as sets, props, lights, and costumes. Technical rehearsals start approximately one week prior to opening night and occur after the initial rehearsal period, which can last from two to six weeks.