Musicians, The Roman de Fauvel, 14th century
This is Bach's Toccata and Fugue in D Minor. It is one of the most familiar pieces of classical music. (It is the opening orchestral work in Disney's original Fantasia.)
Even for the non-musically inclined, we recognize notes, tempo, rhythm. We recognize sheet music and basic notation, even if we don't sing or play an instrument. When we listen, we hear the complexities of rhythm, harmony, and melody woven throughout the piece.
This is the basics of modern musical notation.
Yet this wasn't always the case. The foundation of what would become our familiar musical notation was laid down in the 14th century. In 1322, French cleric and composer Philippe de Vitry wrote a treatise entitled Ars Nova notendi. This treatise would lend its name to a musical movement. The Ars Nova ("New Art") musical style would flourish in France and the Low Countries (Holland and Belgium) throughout the 14th century. (Ars Nova is differentiated from Ars Antiqua ("Old Art") - the musical style of the 13th century.) Ars Nova expanded on previous trends, but one of the most significant innovations was in how music was written down. A groundbreaking change akin to the discovery of perspective in Renaissance art.
In order to understand the importance of Ars Nova, one must take a look at Western music prior to the 14th century. Music was generally sacred, meant to be spiritual and for the church. Beginning in the 10th century, plainchant or plainsong - Gregorian chant is an example - dominated the musical scene. Plainchant is considered to be monophonic. Monophony is the simplest of musical textures. It consists of a single melody performed by a single voice or instrument. Or it could be when a group of voices, such as a choir, sings in unison or at the octaves (male and female voices say).
By the 12th century, some composers were experimenting with adding another voice or voices to enhance the harmonies. Such voices, often on a bass line, would have a parallel melody. This style was called organum and was an early attempt at polyphonic music. Polyphony involves multiple lines of independent melody. Most of our modern music is based on polyphony. Polyphonic music was not widespread and was confined to sacred musical works.
Music at the time wasn't written down like it is today. They utilized a system whose basic element was the neume. Neumes were marks to indicate inflection but were not exact notes to be sung. Neither did they show rhythm or tempo. Later developments varied the heights of neumes to give a sense of relative pitch. The four-line staff followed.
Composers taught the singers what they wanted in terms of rhythm, tempo, pitch, and harmony. If someone else wanted to perform the music, the composer needed to teach them the basic components of the piece. Therefore, most music was transmitted by a long-standing oral tradition. This didn't leave much room for overly complex works of music. Imagine trying to explain to someone how to perform Bach's Toccata and Fugue without the aid of sheet music.
This is where the Ars Nova style becomes important. It established a method of notation that allowed for more complex rhythms. It achieves this by simply subdividing the notational marks into smaller pieces. These new markings would be the basis of our whole notes, half notes, quarter notes, and eighth notes.
The three basic notes are the long, breve, and semi-breve. These could be grouped into twos (imperfect) or threes (perfect). From this arose another subdivision of notes called minims. This allowed for even greater rhythmic syncopation.
The subdivisions were called mode, time, and prolation, and these allowed for four different metrical groupings. These groupings became the forerunners of our modern time signatures. Special marks were created to indicate what grouping was in use.
From the usage of this new notation, the Ars Nova saw innovations in style and harmony. Tenor lines were longer and more complex. They became more of a foundation rather than a melody. The use of talea, repeated rhythmic units, and color, repeated melodic units, were more frequent. The rapid succession of voices, known as hockets, was one of the Ars Nova's most identifiable characteristics. Composers experimented with changing from one meter to another within a work of music. This was shown by a change in the color of the notes and was called coloration. The result was music which was more richly textured than previously. It also allowed for the more frequent use of polyphony in musical works.
One of the most influential figures of the Ars Nova period was Guillaume de Machaut (1300 - 1377). Machaut was a poet and a composer. Though he took religious vows, he spent most of his life and career at the courts of leading French nobility. He applied the innovations of Ars Nova not only to sacred music but to secular music as well.
His themes built upon the older troubadour traditions of France - the ideals of courtly love and chivalric knights. He introduced polyphony to many of the popular French secular musical forms such as the lai, rondeau, and ballade in his poetry and music. With Machaut, not only did sacred music become more rich and complex in texture so did secular music. He contributed to the growing trend away from the predominance of sacred works of music. This was part of a larger shift during the 14th century, in particular after the Black Death, of society turning away from matters of religion to a more worldly focus. This would blossom in the Renaissance where art and music were not limited to great cathedrals but could be found in the homes of wealthy nobles and merchants.
The richness and complexity of our modern music owes itself to the breakthrough in the musical notation of the Ars Nova period. Beyond that, the detailed system of writing music allowed for music to be performed across time and geography. In the end, music would no longer be just for the church or for the wealthy, but music would be enjoyed by everyone.
Further reading:
From Neumes to Notes: The Evolution of Music Notation: Hope R. Strayer