I will say, though, that there's one "interpretation" that always moved me to tears. Channel 4 in OKC, at the time WKY-TV, some years back played a version of the Anthem at sign off with images of the history of our country displayed as the song was played. They went through it twice, and on the second verse, they altered the usual chord progression--as the altered chords played, images were displayed of Teapot Dome, Watergate, and the like, returning to triumphant images and the normal chords for the close.
Let's see if I can remember the changes, which occurred in the section between the "rockets' red glare" and "that our flag was still there"...I'll use first verse lyrics and presume the key of Bb.
And the rockets' red glare Bb Gm7 The bombs bursting in air Cm AbM7 Gave proof through the night Gm Dm F That our flag was still there Bb Gm C7 F