الحماية الفرنسية في تونس
The four pieces which the composer collectively termed "Études de rythme" are not a "cycle" like Messiaen's earlier "Vingt Regards sur l'enfant-Jésus" (1944) or "Visions de l’Amen" (1943). Messiaen composed "Neumes rythmiques" and "Mode de valeurs et d’intensités" in 1949 (the latter at Darmstadt) and added the other two études in the following year, when he was at Tanglewood. The four movements were premiered on 6 November 1950 in Tunis (at that time under the French protectorate of Tunisia) by the composer himself, who shortly afterward made the first recording of the études. The French premiere was given in Toulouse on 7 June 1951 by Yvonne Loriod.