Dufay wrote church music including masses, motets, Magnificats, hymns, simple chant settings and antiphons. His secular (non-religious) music includes rondeaux, ballades, virelais and a few other kinds of chanson. His style of composition laid the foundation for the next generations of Renaissance composers. Some of his techniques were old-fashioned. He used isorhythms in his motets, which had been popular in medieval music. He used a way of harmonizing chants which became known as fauxbourdon. He was popular because he was skilled at writing melodies which were beautiful to sing.