Codifying the Twelve Modes

Glarean added modes on C and A to the eight church modes, and the twelve became the road to major and minor.

Related

RenaissanceMedievalMode

Eight church modes governed European theory for centuries, yet by the sixteenth century they could not explain the growing number of polyphonic cadences on C and A. Glarean expanded the set to twelve, and theory finally caught up with listening.

Time and place

Basel, 1547. The Swiss humanist Heinrich Glarean published the Dodecachordon, a title that literally means twelve-stringed. The eight-mode system itself had taken shape in tonal manuals of the eighth and ninth centuries; the argument now moved from monasteries to universities and printing houses.

What happened

The medieval eight modes were paired as authentic and plagal, each pair sharing one final, with D, E, F and G as the four finals. Reading Ptolemy, Glarean concluded that antiquity had twelve modes, so he added C and A to the four finals, each with authentic and plagal forms, making twelve. He called the mode on C Ionian and the one on A Aeolian. This was not invention from nothing. It gave theoretical standing to cadences on C and A that polyphony already used constantly. The book also compared church modes with ancient ones, turning mode from a tool for chanting into a framework for analysing polyphony.

What changed

Music ending on C or A was no longer a theoretical exception. Printing carried the twelve modes across Europe, composers could discuss their choices by modal name, and theory books now came with musical examples. The consequence was audible. Ionian and Aeolian were later heard as major and minor, so the twelve modes became the road to the key system. By the eighteenth century modal theory gave way to tonality and functional harmony, though textbooks kept the names.

Listen for the turn

Begin with Perotin's Viderunt Omnes, where the chant melody sits in the fifth mode and the added voices circle its final; the modal feel comes from the final, not from a scale table. Then Machaut's Mass of Our Lady, in which four voices have their own finals and the mode must be inferred from cadences. Finally the Agnus of a Palestrina mass, where the voices settle on one final that already behaves like a key. All three can be given a modal number, but the number is the analyst's label, not the composer's instruction.

Related

This turn belongs to Renaissance and follows Medieval; see Mode.

Sources

• Grove Music Online, entry Dodecachordon — publication and modal theory checked, not quoted
• The New Grove Dictionary of Music and Musicians, 2nd ed., entry Mode — medieval eight-mode system checked, not quoted

Used for fact-checking only; all prose is original.