In addition, he was named along with Adrien Basin and Antoine Busnois as "chantre et valet de chambre" to Charles, indicating the special regard in which he was held.
He is known to have been at the Siege of Beauvais in 1472, where Charles was decisively repulsed by the French, and Hayne was long presumed by scholars to have been killed in that battle.
However, recent research into his surviving compositions indicates that some may have been produced after 1472, especially because they seem to show stylistic development beyond the ones that can be definitively dated to 1472 or before.
That such a distinguished singer and composer worked for France's bitter rival would have been an offense easy to forgive, for Burgundian musicians of the time were highly prized.
Eleven pieces can be definitively attributed to Hayne, though numerous similar works classified as "anonymous" may actually be compositions of his.