Luther composed the melody, named "Ein feste Burg" from the text's first line, in meter 87.87.55.56.7 (Zahn No.
 7377a).
This is sometimes denoted "rhythmic tune" to distinguish it from the later isometric variant, in 87.87.66.66.7-meter (Zahn No.
 7377d), which is more widely known and used in Christendom.
In 1906 Edouard Rœhrich wrote, "The authentic form of this melody differs very much from that which one sings in most Protestant churches and figures in (Giacomo Meyerbeer's) The Huguenots. ...
The original melody is extremely rhythmic, by the way it bends to all the nuances of the text ..."
While 19th-century musicologists disputed Luther's authorship of the music to the hymn, that opinion has been modified by more recent research; it is now the consensus view of musical scholars that Luther did indeed compose the famous tune to go with the words.
Luther composed the melody, named "Ein feste Burg" from the text's first line, in meter 87.87.55.56.7 (Zahn No. 7377a). This is sometimes denoted "rhythmic tune" to distinguish it from the later isometric variant, in 87.87.66.66.7-meter (Zahn No. 7377d), which is more widely known and used in Christendom. In 1906 Edouard Rœhrich wrote, "The authentic form of this melody differs very much from that which one sings in most Protestant churches and figures in (Giacomo Meyerbeer's) The Huguenots. ... The original melody is extremely rhythmic, by the way it bends to all the nuances of the text ..."
While 19th-century musicologists disputed Luther's authorship of the music to the hymn, that opinion has been modified by more recent research; it is now the consensus view of musical scholars that Luther did indeed compose the famous tune to go with the words.
A Mighty Fortress Is Our God