[1][2] Only twenty years later did Stockhausen retrospectively discover in the early piece similarities to the formula technique he had devised for his then-latest composition, Mantra (1970).
When asked by Maurice Fleuret for a new work for the 1971 Journées de Musique Contemporaine, Stockhausen offered this score, which he now gave the name Formel.
[3][1] As with several other of Stockhausen's compositions of this period (Kreuzspiel, Spiel, the Schlagtrio, the original version of Punkte, and Kontra-Punkte), Formel gradually transmutes an initial basic pattern of notes into something else.
Its form is chevron-like, first broadening the pitch space out from the centre, then systematically withdrawing notes from the middle until only the outer extremes remain—a sort of inside-out version of the procedure used in Kreuzspiel.
[4] Unlike its companion works, however, the tone row on which it is based is not treated punctually, with notes isolated from one another, but instead they are grouped into melodic cells.