I’ve never noticed any mistakes on Broadway or from official Broadway touring casts. Getting smaller and more regional, more local, I’m sure I’ve seen some flubbed lines but nothing that makes a good story.
I did see singer-songwriter Ron Sexsmith perform on his first “big tour” as an opening act for Aimee Mann. Not to suggest that he is at all “famous” these days, but back then he was even more not famous. His first record had only just come out and, although it met a certain amount of critical acclaim, it didn’t really set the world afire.
Aimee Mann wasn’t entirely a “superstar”, but she was on her second solo album after three Til Tuesday albums and the lead single from the newest album was getting airplay- so, she was playing on the larger side of mid-level venues to sold out or near sold out capacity. So, Ron Sexsmith was undoubtedly playing to the largest audiences he had ever played to.
About two thirds of the way through his set, Ron Sexsmith broke a guitar string.
He had walked out on stage only carrying his guitar, he didn’t have his guitar case sitting right next to him. The stage was too big to just reach off to the wings and grab a string- and his case was probabaly in the green room rather than just offstage anyway. He called for help but no one was paying attention to his set- he certainly didn’t have his own guitar tech on this tour at so humble a point in his career.
After an awkward moment of trying to get someone to hear that he needed help, he told the audience he’d manage the next song without the missing string. He played that song and he played it well, but when he finished the song he made another plea for help. Still no one was paying attention. He strummed a few chords to the next song, but decided he really needed to replace the string.
He apologized to the audience, left the stage for a few minutes, came back with a new string, changed the string, tuned, and played the remainder of his set.
When Aimee Mann came on, she apologized to Ron and to the audience and said that they (as in “we”- she took responsibility) really should have had someone available to help and she felt badly.