| A | B |
|---|
| Acoustics | The quality of sound transmission in a particular building |
| Antagonist | A character in conflict with the main character |
| Auditorium | Area of the theater in which the audience sits |
| Box Office | Area where tickets may be purchased |
| Act | A major structural division in a play |
| Audition | Competition for a part in a play; a tryout |
| Ad Lib | To make up and deliver lines not in the script, usually to cover forgotten lines |
| Book | Script; used chiefly for musicals, it contains the dialogue, but not the music or lyrics, for the show |
| Acting | The performance of a role |
| Amphitheater | A circular or semicircular auditorium or outside area surrounded by raised seating |
| Actor/Actress | Performer in dramatic entertainment |
| Aside | Lines spoken by an actor directly to the audience rather than to fellow actors, who are assumed NOT to hear the lines |
