The "Ambacher Quartett" was introduced into the Alt-Aumund Blockflötenensemble by Britta Albrecht. It was only played once whilst I was with the ensemble. It has four movements: "Mäßig bewegt", "Langsam mit Ausdruck", "Gehendes Zeitgemaß" and "Lebhaft, aber nicht zu schnell". At first glimpse it seems straightforward enough but as you get into there is more to meet the eye in the many changes of tempo and "stretching of bars". The last movement seems to cry out for double-tonguing.
A work best not played by beginners.