Franco-Flemish composer, possibly born in Flanders. Médicis Lorenzo summoned him to Florence, where from 1485 it was singer and composer of the chapel of San Giovanni, and also served at the Cathedral. The death of Lorenzo de Médicis, who dedicated the funeral chant Quis dabit capiti meo aquam?, the cantoria of San Giovanni was dissolved by order of Savonarola. In 1497 he/she was appointed court composer of Maximiliano I, to whom he/she dedicated his Motet for six voices Virgo prudentissima. In 1509 began his Choralis Constantinus, work composed by several parts of trade which was entrusted by the chapter of the Cathedral of Constance for large parties. In 1512, the Medici returned to power, was appointed President della capella and a year later composed the motet Optime... pastor for six voices, which celebrates the pontificate of León X (Jean de Médicis, son of Lorenzo).
The first masses of Isaac are based on secular melodies and by its provision are similar to their contemporary franco-flamencos. In the compound at a later time, text is sung alternately in unison and polyphony, as happens at five masses of the third book of Choralis Constantinus. The preference for this type of mass German style is mainly due to their obligations in the Court of Maximiliano I. His secular compositions are the songs on popular melodies, which are normally cantus firmus (tenor) with instrumental accompaniment. Among the vocal compositions dominate the German songs, with most parts with tenor in the style of the court music.