Change in three stages
The history of music in the Middle Ages is often told in a few broad stages, which are useful as long as they are held loosely. First came the long dominance of unaccompanied chant. Then came the gradual growth of music with several voices. Running through both was the invention of ways to write music down. Each development influenced the others, and each left uneven evidence. Dance, by contrast, changed too, but left almost nothing behind until the very end of the period.
Plainchant
For the early Middle Ages, the main surviving music is liturgical chant: single-line melodies sung in Latin as part of church services. Its shape was modal, built on a set of scales (modes) that gave different chants their colors. Regional traditions existed, and rulers in the Frankish lands, particularly in the 8th and 9th centuries, encouraged more uniform practice, bringing local singing closer to what was understood as Roman custom. The name Gregorian chant comes from the tradition that Pope Gregory the Great inspired the repertory, a story that most scholars treat as legend, though Gregory’s name stuck.
Chant was learned by ear and memory for a long time. Singers kept an enormous stock of melodies in their heads, and the music was linked to the Church year with its feasts and seasons. New chants were added over the centuries, along with embellishments such as tropes and sequences, which expanded existing pieces with new text and music.
Early polyphony
The next major change was the appearance of music in more than one part. A treatise from around the 9th century describes singers adding a second voice that moved in parallel with the chant, usually at a fixed interval below. This early practice is called organum. Over the next centuries the added voice grew freer, sometimes moving against the chant rather than alongside it.
By about 1200, a style associated with Notre Dame in Paris had reached a high level of sophistication. Two names, Léonin and Pérotin, are traditionally linked with the repertory, though what we know about them comes from a later writer, and details are debated. In their pieces, long held notes in the lower voice supported lively upper lines, and rhythm became a more important organizing principle. From these ideas came the motet, in which upper voices could sing different texts simultaneously, sometimes mixing sacred Latin and everyday French.
The 14th century is often described as a period of “new art”, with Guillaume de Machaut as its leading composer. Rhythm became more flexible and complex, and secular forms such as the ballade, rondeau and virelai were written for several voices. Italy had its own parallel style. By the 15th century, composers in northern France and the Burgundian lands, and also in England, were writing smoother, fuller-sounding music that foreshadowed the Renaissance, and the boundary with the next era is a matter of convenience.
Writing it down
Early chant manuscripts used neumes, small signs above the text that suggest the movement of the melody. They worked as reminders for people who already knew the music. Over time, scribes drew a line to fix a particular note, then added more lines until a staff developed. The 11th-century teacher Guido of Arezzo is closely associated with this move toward a clear way of showing pitch. Later, systems for showing rhythm were developed to coordinate multiple voices, since singers needed to know not only which notes to sing, but how long to hold them. This is the foundation of musical notation as we now know it, though the signs looked different and meant somewhat different things.
Writing did not replace memory overnight. Many singers continued to learn by ear, and written music remained concentrated in churches, courts and schools.
Songs and instruments
Secular music also changed. The troubadours emerged in the late 11th and 12th centuries, followed by trouvères and German Minnesinger, and their songs were eventually written down in books, some with melodies. Instrumental music is harder to trace. Over the centuries, new instruments arrived or became popular, including lutes, shawms and keyboard instruments, and the sounds of town and court music gradually changed with them. But most instrumental playing was improvised or learned by ear, so notation for it is rare until late in the period.
Why so little dance survives
Dance is the great gap. Steps were taught in person, by example, and there was no need to write them down. Pictures show dancers in motion and sources mention dancing, but for most of the Middle Ages there are no step descriptions. A handful of instrumental dance tunes, such as the estampie, survive in manuscripts, though it is not always certain that they were used for dancing. Only in the 15th century do detailed descriptions appear, mostly from Italy and the Burgundian lands, and they concern court dances, not village ones. This means that any statement about the “evolution” of dance before about 1400 is based on indirect clues.
Reading the pattern
One way to summarize the story is that music became more written, more complex and more individual over time, while dance remained largely an oral and bodily tradition. Another is to remember what the evidence favors: church music is documented far more thoroughly than the music of ordinary people. The line from chant to polyphony is real, but it shows the part of the story that people had the means and reasons to preserve.