Jacobus non Papa Clemens (1510-1557) was a Franco-Flemish composer actually known as Jacques Clément. It is not definitely known why he called himself "non Papa"; perhaps to differentiate himself from a Jacobus Papa who also lived in Ypres.
In 1544 he was named songmaster at St. Donatian church in Bruges, and in 1550 called to the post of singer and composer at the cathedral in Herzogenbusch.
His music, which followed in the tradition of Josquin Desprez, was famous for its melodiousness. He is one of the most significant composers of masses and motets before Palestrina. His compositions, which after four hundred years are easily accessible today, enjoy great popularity.