There is definitely something to all this, although it is perhaps not quite as pat as the authors suggest. It is well-known that Ford subscribed to anti-Semitic views, which were expressed in the early 1920s his own newspaper, The Dearborn Independent, later reprinted in the four-volume International Jew. Faced with a libel suit in 1927, Ford apologized for the editorials, and denied that he was their author - although much suggests neither the apology nor the denial were sincere.

Ford was also a music aficionado, and some of the editorials identified the dominance of Jews in the music and other cultural industries as a threat to the moral health of the country. For example, in 1921 the Dearborn Independent railed against the Jewish influence in modern American music:

It is the purpose of this article to put people in possession of the truth concerning the moron music which they habitually hum and sing and shout day and night, and if possible to help them to see the invisible Jewish baton which is waved above them for financial propaganda purposes. Just as the American stage and motion picture have fallen under the control of Jews and their art-destroying commercialism, so the business of handling "popular songs" has become a Yiddish industry. The Jews who captured it in the early days of exploitation were for the most part Russian-born Jews, some of whom had personal pasts which were unsavory as the past of many Jewish theatrical and movie leaders have been exposed to be.

In Ford's view, the cities and everything they represented - licentiousness, defiance of Prohibition, immigration, and modernity generally - were the antithesis of what American culture ought to be. Echoing German concerns about the "race-soul" of the nation, Ford felt that Anglo-Saxon traditions ought to be preserved and promoted to push back against the influence of the "international Jew" - the symbol of rootless cosmopolitanism and modern degeneracy.

The music industry was to be a battlefield where this struggle was to be fought, in Ford's view. Not only jazz, but also Tin Pan Alley, and the entire music business was a means by which Jews poisoned the national culture:

The people are what they are made. Give the liquor business full sway and you have a population that drinks and carouses. The population could be turned into drug addicts if the same freedom was given to the illicit narcotic ring as is now given to the Yiddish popular song manufacturers. In such a condition it would be stupid to attack the addicts; common sense would argue the exposure of the panderers. A dreadful narcotizing of moral modesty and the application of powerful aphrodisiacs have been involved in the present craze for crooning songs - a stimulated craze. The victims are everywhere. But too few of the opponents of this moral poison see the futility of scolding the young people thus diseased. Common sense dictates a cleaning out, and a clearing out, of the sources of the disease. The source is in the Yiddish group of song manufacturers who control the whole output and who are responsible for the whole matter from poetry to profits.

In response to this perceived threat, Ford devoted a great deal of energy to promoting "traditional" Anglo-Saxon music and dancing. Between 1925 and 1927, he hired hundreds of dance instructors to teach folk dancing in Ohio and Michigan, using his own publication ('''Good Morning': After a Sleep of Twenty-Five Years the Old-Fashioned Dancing Is Being Revived by Mr. and Mrs. Henry Ford") as an instruction manual. He had stages built for the classes, and enlisted dozens of accomplished fiddlers to act as accompanists. He sponsored fiddling contests at his car dealerships (although he was at times dismayed by the immoral conduct of the performers).

By the late 1920s, Americans were purchasing radio sets in growing numbers and Ford turned his attention to broadcasting, creating the half-hour "Early American Dance Music" radio program, which was broadcast from the Ford Motor Company's recording studio in the engineering laboratory. In the ensuing decades, he also used philanthropy as a means of purchasing instruments and financing music programs in Southern high schools.

While there is no "smoking gun" that links Ford's anti-Semitism to his promotion of the square dance, there is a great deal of evidence that suggests his broader view of American culture - as a site of struggle between rural, Anglo-Saxon traditions and urban, Jewish modernity - was an important rationale for his patronage of traditional music and dance.

Sources: Emery C. Warnock, "The Anti-Semitic Origins of Henry Ford's Arts Education Patronage," Journal of Historical Research in Music Education, Vol. 30, No. 2 (Apr., 2009), pp. 79-102; Morroe Berger, "Jazz: Resistance to the Diffusion of a Culture-Pattern," The Journal of Negro History, Vol. 32, No. 4 (Oct., 1947), pp. 461-494 (esp. 463); Colin Quigley, "Reflections on the Hearing to 'Designate the Square Dance as the American Folk Dance ofthe United States': Cultural Politics and an American Vernacular Dance Form," Yearbook for Traditional Music, Vol. 33 (2001), pp. 145-157

This is tangential but why wasn't there a boycott of Ford Motors after 1945?

Yes, HF was a very complex man, but certainly a large part of his worldview was influenced by his rural agricultural upbringing. And to call it a worldview is a bit paradoxical as that kind of upbringing, so to speak, is typically lacking in information about the world at large. Though I make no claim to be a scholar on the subject of HF’s antisemitism I have read about it for many years and I am inclined to think it was much more about the perception of the role of Jews in finance and banking, than typical racism. To say HF was not a fan of Wall Street would be an understatement. This article and comments makes a lot of good points about the paradox, such as his employment of Albert Kahn, a Jew, as architect of most of his pre-WW2 buildings and plant facilities, including most notably the Rouge complex. He was also well ahead of his time in the employment of blacks, women, and the disabled in his operations.

It is also easy to vilify the man for his cozy relationship to Hitler in the late 1930’s, but keep in mind, Ford had a substantial investment in operations in Cologne Germany that predated the rise of Hitler to power. That said, once hostilities started, Ford was very involved in arming our allies, and After Pearl Harbor the company went all out for the war effort. The B-24 bomber, produced at the newly created Willow Run plant is well known for producing bombers at a rate of one per hour at its peak, thanks to the company’s expertise in mass production. Ford could produce them faster than the Luftwaffe could shoot them down, and this hastened the end of the war. Ford was involved in the production of many other kinds of war materiel as well.

As for why no boycott after WW2, by then HF was senile and the company was being run by his grandson, Henry Ford the 2nd, son of Edsel Ford who had predeceased him. Edsel was well known as a fan of Jazz and sophisticated living including fine wine, both of which HF objected to. Edsel Ford of course, unlike his father was raised in the very booming city of Detroit and had as a result a very different view of the world. Edsel and his decendents did not share HF’s antisemtism and were in fact of very self conscious of the views of their patriarch. They actively worked to reverse the damage done to the Jewish community in the aftermath of WW2.