It’s important to know that there’s a musical joke here. The singer should be onto the joke, and not hesitate to sharp that fourth. Most singers pause slightly to express their bewilderment at a sharp that doesn’t belong in the melody.

Leonard Bernstein does a riff on the “meaning” of thirds, fourths, fifths, etc. Fifths are very hopeful, he says. If you were to use Bernstein’s logic, you could say that the arrival at the fifth by modeling the arrival at the tonic of the next higher key suggests that Americans are hopeful by nature. And basically that’s what the National Anthem suggests. Much is made of “rockets’ red glare” but the real catch is to sharpen that fourth in the second phrase. That’s the central conceit of the tune.

I remember the time I was at a Yankees Blue Jays game and this poor hapless young woman who did a pretty good job with the National Anthem forgot the words to O Canada and just stopped. But she waas a trooper and started again. And forgot again.

In 2005 singer Sarah Connor messed up the lyrics of the German anthem. Translated to English she the wrong line was “broil in the light” instead of “bloom in brilliance”. This was widely exploited by the yellow press, comedy TV shows and of course the internet…