“If the truth were known about the origin of ‘jazz,’ it would never be mentioned in polite society,” wrote Clay Smith in Etude magazine in September 1924. A trombonist who had toured Western mining towns in the 1890s, playing in honky-tonks where “the vulgar word Jazz was in general currency,” Mr. Smith knew what he was writing about.

The word was African-American slang for copulation, both as a noun and as a verb. Jazz in its various forms— jass , jasz , and jaz are among the early spellings—may derive from some African language, though no connections have ever been proved. The term has secondary senses of excitement, energy, and invigoration, often in such constructions as jazz up , to enliven; jazz around , to fool around; and jazzy , lively or snappy. To demonstrate the word’s original shock value, Raven I. McDavid, Jr., added the following footnote to his one-volume abridgment of H. L. Mencken’s The American Language : “According to Raven I. McDavid, Sr., of Greenville, S.C., the announcement, in 1919, of the first jazz band to play in Columbia, where he was serving in the legislature, inspired feelings of terror among the local Baptists such as what might have been aroused by a personal appearance of Yahweh. Until that time jazz had never been heard in the Palmetto State except as a verb meaning to copulate.”

Conveying the flavor of the word more explicitly is the heading of a note from one girl to another included in an article by Charles A. Ford in The Journal of Abnormal and Social Psychology in 1929: “You can take my tie / You can take my coller / But I’ll jazze you / ‘Till you holler.”

The association of the word with the music is hardly surprising, considering that jazz flourished initially in the steamy atmosphere of New Orleans brothels. The earliest example of musical jazz in J. E. Lighter’s monumental Historical Dictionary of American Slang is from 1916: “The shriek of women’s laughter rivaled the blatant scream of the imported New Orleans Jass Band, which never seemed to stop playing.” (The shrieking women would have been called jazz babies , a term that also dates from this era.)

The transfer of the sexual term to music may have been made via the word’s secondary meanings. Lafcadio Hearn, who spent time in New Orleans in the late 1870s and early 1880s, studying local life and customs (and who was fired for not filing stories on Louisiana politics as expected by the Cincinnati newspaper that had sent him there), reported in 1917 that “the word ‘ jaz ,’ meaning to speed things up, to make excitement, [had been] common among the blacks of the South and