But when Andrew Rannells was offered this opportunity of a lifetime, things didn't exactly go as planned.
During an appearance on The Tonight Show, the actor told host Jimmy Fallon about his five-week stint filling in for Jonathan Groff as King George in the hit show.
"You have one song, I think it's nine minutes of stage time total, and you come out and you do this song and you're all along on stage," Rannells told Fallon. "It's a great part but I was nervous, obviously, to sort of be dropped into the show."
Everything went well for his first four shows, the Girls star, 37, said, but disaster struck during the fifth performance.
"I walked out there and I was like, 'You say –,' nothing. Not a single – I couldn't remember the next line, nothing," Rannells said. "I made a bold and maybe incorrect choice that I kept moving my lips so that I was like, 'Maybe they'll think my microphone went out.' "
Rannells quickly shut down Fallon's claim that this was a "genius" idea.
"No, I Iooked like a crazy person, like I was on Toddlers and Tiaras," he said. "And then finally Alex Lacamoire, the conductor, yelled up a lyric and I was like, 'Thank God,' so I was back, but it was the longest eight seconds of my life."
Ah, the excitement of live theater!