Francis Scott Key wrote it as a poem, not a song. It was only later set to music. When the character in Angels in America made the comment about how it the song was written poorly (paraphrase), he was displaying his ignorance of this fact. No surprise there.
I'm guessing that context would reveal that line to either be a joke or an intentional depiction of an ignorant character. In any case the music doesn't fit the lyrics.
"Francis Scott Key wrote it as a poem, not a song. It was only later set to music. When the character in Angels in America made the comment about how it the song was written poorly (paraphrase), he was displaying his ignorance of this fact. No surprise there."
No, he had the tune specifically in mind. In fact, he had written other lyrics for it previously.
"To Anacreon in Heaven" was very popular for setting to patriotice music. There were versions called "Adams and Liberty" and "Jefferson and Liberty" before TSSB. And many others besides.