Five movements. Movements 1, 3 and 5 are on 4 notes: C, D flat, F sharp and G, and their octave transpositions.
Movements 2 and 4 use a 12-tone note row.

Suite for Solo Trombone p1 – movements 1 and 2

My student colleague at the Cambridge summer school in the early 60s, Robin Maconie (later famous as Stockhausen biographer1), wrote a piece for string quartet using just two notes (E & F, in all possible octaves). I don’t remember ever hearing a performance of this but the score alone impressed and inspired me. Nevertheless I have never used just two notes, with the exception of “As I Joseph was walking”—the first song of 4 Carols on 4 Notes in which just C and D predominate.

1 *Maconie, Robin. 1976. The Works of Karlheinz Stockhausen. London, New York, Toronto: Oxford University Press