Live event audio traditionally relies on a left/right mixing and loudspeaker array format for sound reinforcement systems. This is similar to the dominant left/right (stereo) format for consumer electronics, which began with stereo recordings, high fidelity systems for the home, and L/R headphone products. Today’s immersive live audio systems are viewed as evolutionary extensions of early quadraphonic concert systems such as were deployed decades ago by classic rock acts like Pink Floyd and The Who. Additionally, cinema sound trends over several decades and performance-venue fixed installations that have evolved from multi-channel theater sound platforms are examined. With audio object-based software tools and application-specific digital signal processing now available, the current generation of immersive audio platforms for live sound reinforcement is reviewed. Future trends are considered.