One of the most famous (and terrifying) examples happened during a massive outdoor tech product launch in the early 2000s. The "Invisible" Piano
The pianist agreed. The audience was none the wiser; they saw a gorgeous grand piano over the water and heard world-class audio. The event was a triumph, and the stage held firm. Events Management
They gutted a high-quality electric keyboard and mounted it inside the shell. One of the most famous (and terrifying) examples