Quercu, Eijcken, Eyken, Simon de, Simon van, *Brabant, †1st half of the 16th century, Netherlandish music theorist. In 1509, he published a treatise entitled Opusculum musices in Vienna, in which he is referred to as a Brabantine and “cantor of the Dukes of Milan.” In his dedication to them, Quercu calls them “diligent pupils.” He is probably referring to the sons of Ludovico Sforza, who were in exile at the court of Maximilian I, Holy Roman Emperor, in Vienna at the time. He also published there (1513) a book of songs in the Paduan rite, Vigiliae cum vesperis et exequiis mortuorum. The treatise, in which Quercu discusses the principles of choral and polyphonic music, contains a relatively early description of mensural notation. It also includes guidelines for tuning keyboard instruments, as well as consonance tables using 14 lines for counterpoint from 2 to 6 voices. The work is notable for its scholarly and somewhat obscure terminology.
Literature: H. Ristory Die Mensurallehre des Simon de Quercu, “Zeitschrift für Musiktheorie” VI, 1991; F. Diergarten Eine Musiklehre vom Hofe Maximilians: Simon de Quercu und das Opusculum musices, “Troja: Jahrbuch für Renaissancemusik” XVIII, 2018.
