Final answer:
Richard Wagner was the leader in the grand opera style, known for his unique approach in creating immersive theatrical experiences with innovative concepts like the orchestra pit.
Step-by-step explanation:
The leader in the grand opera style who employed every available technique to dramatize the action and please the public was Richard Wagner. Wagner was a trailblazer in the Romantic era and was known for not only composing operas but also for his innovative ideas in theater, such as the creation of the orchestra pit. His goal was to create an immersive experience where the music supported the action on stage without the audience seeing the orchestra.
Wagner's developments went hand-in-hand with the grand opera style, employing leitmotifs, rich orchestration, and a seamless flow between scenes to create a cohesive and powerful narrative, revolutionizing the opera.