Why did one of the most memorable Tonys moments occur during a commercial break?

On Monday night's Late Late Show, James Corden showed footage of Billy Porter singing "Everything's Coming Up Roses" shot during a Tony Awards commercial break. "This is the epitome of what the Tonys telecast should and could be -- joyous, spontaneous, theatrical in pink neon capital letters," tweeted critic Mark Harris. "And it happened during a commercial break." Meanwhile, Porter responded to the video, tweeting: "It's always been a dream to do carpool karaoke with @JKCorden, so you KNOW I had belt out when he asked me to do it at @thetonyawards."