A somewhat controversial article in which Idelsohn tries to show traces of Jewish music in French folk music. Jews settled in France in the fourth century; "they were scattered throughout the country and lived mingled with the native people" until the fourteenth century when they were expelled twice, first in 1306 and for the second time in 1394. There are various testimonies showing that the Jews influenced the non-Jewish population and even that "Christians learned from the Jews the chants of Psalms." Therefore "we may assume that elements of Jewish religious and folk traditions crept into the folk traditions of the population in France." Idelsohn prepares his comparison of French and Jewish melodies with introductory remarks about the "predominance of certain scales" in folk music of various peoples, the tendencies of certain peoples towards rhythmical or unrhythmical songs, and the longevity of folk tunes. He also states his belief that "the originality of a people's song is expressed primarily in its melodic line and in the formation of its motives" and that consequently people usually reshape foreign melodies when they adopt them. "But whenever the mode has originally grown out of the tonal expression of some racial element merged into the new nation, the melodic line is but slightly changed." Idelsohn reminds us that many nations influenced French folk tunes and endeavors to show that traces of the magen avot shtayger as well as the "melodic line of the Yemenite 'Selicha' mode of the Prophets and that of Psalms" are found in fourteen French airs which were notated in the fifteenth century but are probably several centuries older. The article provides comparative analyses of about fifty Jewish, French and other tunes. It ends with the question whether "all these comparisons offer merely another example of 'Wandering Melodies'" or whether the similarities are "a result of ethnological fusions." Idelsohn is aware of the difficulties of his thesis and calls for "an intense study" of "more and ampler material."