I owe my understanding of the origin of many instances of the FuTesatefu effect to Joel Rosen's often delightful book, Symmetry, but I'll explain this particular conek in terms of loconeks familiar to all or most of you -- such as blowing on a grass blade, and blowing on the mouth of an empty bottle (mentioned by Rosen) -- and a less familiar one, which I experienced when young -- blowing on a wind instrument, such as "digging that crazy trumpet!"You blow on a grass blade lying on your tongue. The wind flows symmetrically on either side of the blade -- a fluent process: the first "Fu" of "FuTesatefu". But "something" can "cause" an asymmetry of flow -- greater on one side than the other -- invoking oscillations in the flow: the "Te" tremblant forming the second stage of the "FuTesatefu" process. Then this asymmetry invokes a "jump" and a "ragged" tone emits -- the salient, "sa", forming the third and medial stage of the process. After going through its own oscillation, or tremblant phase (the "te" forming the fourth stage of the process), it then stablilizes into a "smooth" tone: the final fluent "fu" of the process.
The process of blowing on the lip of the bottle is (presumably) similar. (If you doubt this, PROVE OTHERWISE!)
Anent the trumpet. My impoverished childhood and youth was ameliorated by a blessing perhaps found nowhere today, due to a Scotsman named "R. Ritchie Robertson". Robertson had come to America as piano accompaniment for Sir Harry Lauder, one of the stars of the international vaudville circuit. (There's a scence in the film, Yankee-Doodle-Dandy -- which won Jimmy Cagney an Academy Award -- when Jerry Cohan, played by Walter Houston, tells his family that the famous Sir Harry Lauder has come to America. This is when Ritchie came.)
Ritchie Robertson liked America and stayed to play in various instruments in the famous bands of the day, such that of John Philip Sousa and Edwin Franko Goldman. Ritchie visited a relative in St. Louis and found his way down to Springfield, which he made his home, as Music Director in the Public Schools.
Ritchie founded "The Boy Scout Band", which became three marching bands of around 100 boys each. You could start (at age 9) in the Monday Night band. After a year, you usually graduated to the Wednesday night band. If you were good enough, you were promoted to the Thursday night band, which did most of the performing in pardades and concerts. But Ritchie could, if needed, put over 300 boys on the street. We marched in parades, gave concerts, and (with our own buses) participated in musical and civic events all over Southwest Missouri, up to St. Louis, playing for the St. Louis Cardinal ball games.
Ritchie also formed "The Girls Fife, Drum, and Bagpipe Corps", for high school girls in kilts who marched with us in the parades. It was the fantasy life of "Music Man" made real!
I started playing a Navy bugle at age 7 and, at many schools, blew "To the Colors", at morning flag-raising; "Taps", at afternoon flag-lowering. At age 11, I joined the Monday night Boy Scount Band; went to the Wednesday night Band when 12; and the Thursday night Band when 13. Ritchie might have try-outs during every rehearsal. One glorious night, I pleased Ritchie enough to go from the first trumpet on the fourth row to the last trumpet on the first row. I gradually worked up to eighth place on the first row. Then I got lazy and diverted and slipped back. But I had five great years, playing marches and arrangements from "The Classics". Nothing like this exists today, particularly not in Springfield. Even the coddled bands for sports events have nothing to compare to this experience.
I also learned to play pop music and some jazz. Later, I played trumpet in marching bands in the Army Air Corps, during World War II. And I played a little in the Symphony Orchestra at Inter American University of Puerto Rico, where I was Head of the Mathematics Department. I still have a trumpet but haven't had time for it for years.
This apparently inspired our oldest son, Tim, to take up electric bass in a Rock group, go on to jazz and pop, then symphonic music. He obtained a B.A. in music, M. B.A. in music management, and, for years, has been Head of the Music Department of Elmhurst College near Chicago, where he also moonlighted in a swing band and in small ensembles.
And, in my head, I still "dig that crazy trumpet", which -- as with any wind instrument -- works by the FuTesatefu effect.