Guidonian
adjective
Gui·do·ni·an
gwēˈdōnēən
: of or relating to the theories of medieval music theorist Guido d'Arezzo
especially : relating to his system of solfège and theory of movable hexachords
Word History
Etymology
Guido d'Arezzo (also called Fra Guittone) †about 1050 Benedictine monk and musical reformer + English -ian
First Known Use
1721, in the meaning defined above