A huge social and cultural history lies in the microcosm of this two-note rhythm. Questions dealt with inv;ude:  What is a "Scotch snap"?  How does it relate to language, class and ethnicity?  Is it just Scottish, or is it also Irish, Welsh, English, West African, Hungarian, "Celtic", "black", "white" or what?  It's used by Henry Purcell, Béla Bartók, Mahalia Jackson, Woody Guthrie, Stevie Wonder, Ry Cooder, James Brown and Buck Owens; and you'll also find it in Strathspeys, traditional English ballads, Appalachian fiddling, string band music, spirituals, white gospel, black gospel, even in West African time lines, but you won't hear it in mariachi, mbaqanga or MPB, nor in music of South or Central Europe: why and why not?  It has to do with English language rhythm but then why did the snap disappear from English music during the 18th century to re-emerge globally in popular musics of the late 20th century?  Why did Dvořák think that "Negro" and "Scottish" musics were similar?  How come some music of English origin is labelled "Celtic" when England is seen by fans of "Celticity" as the devil incarnate? This instructive but entertaining video offers an alternative to ethnic fixations in popular music history and genre labelling.