During this period he studied with Heinrich Isaac, serving as his copyist by 1509; he is known to have copied much of the older composer's Choralis Constantinus, an enormous work which he was later to complete after Isaac's death.
Selle aja jooksul ta õppis Heinrich Isaac, olles oma matkija poolt 1509, ta on teada, et on kopeeritud palju vanem helilooja Choralis Constantinus, tohutu töö, mida ta oli hiljem täita pärast Iisaki surma.