The song "The Star Spangled Banner" has been the national anthem of the United States since 1931 and was popular for nearly 100 years before that.

A few things are distinctive about the way in which the song is performed:

• Whether sung or performed by one or more vocalists, the last few lines (sometimes starting with "O say does that star spangled banner yet wave..." and sometimes with "o'er the land of the free...") are performed in a much slower tempo than the rest of the song.

• the "o'er the land of the free and the home of the brave" part, when sung, is filled with indulgent vocalistic flourishes.

• performers are very, very liberal about arranging the song.

One might think that the national anthem, being an icon of the country, would be performed in a very traditional and customary way, for the sake of showing dignity and respect for a national symbol. Yet the reverse is true for this song. How did this come about? Has "The Star Spangled Banner" always been arranged and interpreted so freely, or is this a recent phenomenon?