Here is a fantastic example of how to handle those performance glitches. This is from jazz singer's Ella Fitzgerald 1960 performance in Berlin. Partway through, she completely blanked out on the lyrics. True to form, she improvised flawlessly. She was rhyming, she made up lyrics that really made sense. She didn't lose her cool and just went along with it - and it sounded just fine. More than fine.
Too bad I can't find video for this one. You'll have to just imagine yourself there. Enjoy!
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