Concert in the Egg
attributed to Hieronymus Bosch
the score from which they’re singing is by
Crecquillon.

Thomas Crecquillon or Créquillon (c. 1505 – probably early 1557) was a Franco-Flemish school composer of the Renaissance. While his place of birth is unknown, it was probably within the region loosely known at the time as the Low Countries, and he probably died at Béthune.

Unlike many of the composers of the Franco-Flemish school, he seems never to have left his home region for Italy or other parts of Europe. Crecquillon was retired by 1555, and most likely he died in 1557, probably a victim of the serious outbreak of the plague in Béthune that year.

The printers Petrus Phalesius the Elder (of Leuven) and Tielman Susato (of Antwerp) published more music by him than by any other composer, which shows the extent of his reputation at the time.