Isaac or Isaak, Heinrich
(many spellings extant), b Flanders, Brabant, Belgium (or S Netherlands or Germany) c1450, d 1517 or 1527. He is known to have been an accomplished composer by the 1470s, but is first heard of directly in 1484 at Innsbruck, Austria, probably en route for Italy. By the following summer he was singing in the cathedral at Firenze (Florence). Being in the service of the Medici family, his marriage to a Florentine lady seems to have been arranged by Lorenzo ‘the Magnificent’. After the death of the latter, whose family Isaac probably taught, the Medici choir disbanded and he became court composer in Vienna to Emperor Maximilian I. He continued to visit Florence while living at Konstanz 1507– 08, starting work on his major compilation of choral music for church services, the Choralis Constantinus (finally completed by his pupil Ludwig Senfl and published in 3 vols 1550–55, highly praised 4 centuries later by Albert Einstein). When the Medici family regained power in 1514, he received a pension (150 florins p.a.) in Florence, authorised by Lorenzo’s 2nd son, recently elected Pope Leo X at the age of 38. He probably remained in his adopted city for the rest of his life (whether 3 years or 13) and in the country where his fame was the greatest, being known as ‘Tedesco’, or Harry the German. But his material fortunes did not last, and he is later reported to have been in Rome ‘old, sick and without means’. He was a prolific composer of music, instrumental and vocal, sacred (masses etc) and secular; see notes in Grove. No.558=790.