Music notation, created in the ninth century, took a long time to change how music was composed. But eventually it led to new ways of thinking about music.
In the ninth century, European musicians began experimenting with notations to record plainchant. The initial notations were rough. They didn’t precisely denote either pitch or rhythm, and were intended more as an aid to memory than as a recording medium. But they improved. In the 11th century, Guido of Arezzo introduced the musical staff, making it easy to record pitch. And in the 13th century, Franco of Cologne suggested using a written note’s appearance to signify duration. These and many other ideas led to modern musical notation.
Written music originated as a recording medium, but became a creative medium in its own right. It made it much easier to compose complex, intricate music for many instruments and voices. This paved the way for Bach’s fugues, Beethoven’s symphonies, and much else. Written music became a medium for thought, a medium which expanded the range of musical ideas a composer could have, and thus changed music itself. It’s an example of a cognitive medium – a media environment to support and enable thought. (Source)
Age of the Incunable shows a similar process with print.