The Gregorian (Plainchant) was the first use of classical music by the Roman Catholic Church. It wasn’t until the ninth century that the chants were written down; until then it was all memorized. This music was monophonic (one voice) used by the religious.
The secular world took upon classical music in the form of troubadours and their poetic melodies. Still simple in nature, the melodies became complemented with instruments.
The 10th and 11th centuries brought western classical music into a polyphonic mode with harmonies being added and yet more instrumentation. Leonin, Perotin and Guilliaume de Machaut were some of the composers of the day. Leonin further advanced the history of music with the formation of motets.
Ceremonial motets were created by Guillaume Dufay in the 15th century while the liturgical pieces grew by leaps and bounds. The ordinary mass in the Roman Catholic Church was highly vocal with the lines borrowed from the older chants. Josquin des Pres created one of the more famous masses. From the mid-16th to the beginning of the 17th century madrigal music was introduced into the classical fold. Up to five voices were included in these pieces. Jacques Arcadelt was one of the best known composers.
Instrumental musicals also made their debut. It would either be danced out or sung and would intersect the human experience with the classical sound. Michael Praetorius is famous for this method.
From 1600 through 1750, western classical music yet again gained momentum. There was more interest in the solo voice and more instruments were sought. The Florentine Camerata was formed by members who wished to create a staged musical experience. Jacopo Peri wrote "L’Euridice," a play about Orpheus and Eurydice.
Martin Luther gathered many tunes and rewrote them as Protestant hymns. Johann Sebastian Bach composed several chorales, arias and solos for the church numbering into the hundreds. "The Messiah" is the most famous piece from George Friedrich Handel, originally written in a bar for four voices. Sonatas also were introduced in this time period. A beautiful keyboard piece is "Four Seasons" by Vivaldi while Frescobaldi highlighted the toccata manner of play.
The end of the 18th century brought western classical music the reformation of opera through composers that included Willibald Gluck. Solo keyboard music was introduced by the son of Johann, Carl Philipp Emanuel Bach (CPE Bach). Symphonic music was given to us by Sammartini and Haydn gave us several pieces with string quartets and timpani that echoed the wars surrounding his life. Mozart was a child genius who wrote opera, masses, comedy and other unmatched masterpieces. Beethoven studied under Haydn and his famous "Symphony No. 5" is modeled after the sonata, however, the opening and the coda of the piece are earmarks of Beethoven’s work.
Orchestral pieces were created by several composers during this period, which included Schumann and Mahler. Music in the Romantic period provided western classical music with a narrative set to instrumental music, allowing the listener to follow the storyline solely by the instrumentation alone. Berlioz was a master while Chopin’s piano pieces moved into different styles to include ballads, etudes and Polish dance. Verdi gave us the bel canto style of singing with his music of flowing melodic tunes in which vowels were emphasized. Wagner introduced operas that were equal parts music and vocals to add drama to the messages of the plays. Brahms on the other hand gave the world a more tranquil method of music that included his famous lullaby, still sung by mothers the world over. Mahler had several symphonic pieces under his belt with some bringing in a folk poetry element.
Debussy used the age-old methods of the western classical composers before him and infused his music with harmonic methods gained from Russia and Asia. He was considered an impressionist to the music world. Stravinsky lived from 1882 until 1971 and wrote several scores that included his Russian folk music background as well as ballets. Charles Ives came from America and wrote classically with instruments and voices that would blend several forms, including country church, dance hall and military music (which included such hits as "Yankee Doodle"). Bela Bartok wrote tunes based on his Hungarian folklore while Arnold Schoenberg wrote in an atonal style. Copeland is famous for American folklore that includes "Spring."
Other composers of these centuries include Shostakovich, Messiaen, Legeti and Stockhausen. Mysticism, military sounds, synthesizers and atonal forms took hold under these masters.