Does anyone know the source for Rochut etude no. 1? Rochut 2-14 and 16-25 all come from Bordogni's 24 Vocalises faciles et progressives, but I can't find no. 1 in any Bordogni books I've looked at (although I may have missed one). A RISM incipit search also didn't turn up anything. Many years ago a ...