Richard Quesnel is the true heir of the great British tradition of choir schools. He is graduated from the University of Cambridge. He also obtained his agrégation in music and the college diploma in choral conducting. He worked with the choir school of Caen, then he became a choirmaster in the Académie de Musique et d’Arts Sacrés de Sainte-Anne d’Auray. He composed many sacred songs for choirs. He arranged traditional Breton songs and secular songs. “O Crux ave, spes unica” is a Latin expression in “Vexilla Regis” which means “Hail to the Cross, our only hope.” It was composed for the transfer of the Holy Cross from Jerusalem to the Abbey of the Holy Cross, Poitiers. He was sung on November 19, 1569. This is the last sheet music of an unaccompanied collection composed for the Holy Week, and the highschool choir of the Académie de Musique et d’Arts Sacrés de Sainte-Anne d’Auray. The homorhythm and the comfortable ambitus make the sheet music easy to learn. You are free to try some things. Mentions of tempo and touches are only suggestions.