Killmayers first composition was "Lorca-Romanzen" after Federico García Lorca, premiered at the Donaueschingen Festival. In 1954 he composed a Missa brevis, which was recorded and reviewed:Young (29) Munich-born Composer Wilhelm Killmayer's Missa Brevis ripples with exciting, shifting rhythms and rises skillfully to a colorful series of blasting choral climaxes occasionally more reminiscent of the bandstand than the choir.