Dame Joan Sutherland: Sometimes a singer is given only a few brief chords of music before they are expected to sing. Here, Dame Joan Sutherland had trouble hearing the notes on which to enter. (Watch the YouTube video.)
Placido Domingo: A myriad of factors can contribute to a cracked voice. In this clip from the Met's 1987 production of Turandot, Placido Domingo experiences an unfortunate crack in his voice. Where many inexperienced singers may drop character, Domingo keeps on singing as if nothing happened. (Watch the YouTube video.)
Luciano Pavarotti: Even the great Pavarotti's voice cracks. But just like Domingo, Pavarotti keeps singing without giving second thought. He actually sings beautifully throughout the entire recording. Towards the end of the piece (around the 3:10 mark), Pavarotti's voice cracks and even garners a laugh from the audience. However, he still receives a hearty round of applause at the end of the song. (Watch the YouTube video.)
Roberto Alagna: Let this serve as a lesson of what not to do. In 2006, during just the second night of the operatic season, tenor, Roberto Alagna stormed off the stage during the first act after he received booing from the audience. His understudy was so quickly rushed to the stage, he had no time to change into costume. It's only human to have "off" days, but it's also only human for people to express their opinions (whether they're appropriate or not). You just have to suck it up and move on. (Watch the YouTube video.)
Lastly, here's a final video of a collection of operatic bloopers, mostly consisting of cracked voices. (Watch the YouTube video.)
