It wasn’t long before musicians figured out they could use notation to write several tunes into the same song: tunes that harmonize with or play against the main tune and enrich it. This is called polyphony.
Alcuin’s invention makes it possible to write fugues and symphonies and operas with parts for an entire orchestra of musical instruments and many human voices. Other cultures nowadays may write and perform symphonies, but they couldn’t do it without Alcuin and Charlemagne and the Holy Roman Empire.
Here are a couple of quick explanations of how musical notation works:
Mediæval music manuscripts are a lovely combination of lettering and notes. https://sites.google.com/a/umich.edu/from-tablet-to-tablet/final-projects/music-in-medieval-manuscripts
Here are the Mediæval Bæbes to show us what the Middle Ages sounded like—https://www.youtube.com/watch?v=RXrdfTSLWCY
Likewise Carlo Gesualdo (he’s the composer; I can’t find who performed the Tenebrae Responsories for Holy Saturday in this recording)—
You sure can’t beat the Tallis Scholars—
Girls could play the game, too. In the 1100s, divinely-inspired Sister Hildegard von Bingen created this music—
Eventually (ad 1700s—see the sketch above) we got Johanne Sebastian Bach writing stuff like this. I believe the bottom staff has the main tune while the top staff has all the deedle-deedle-deedle (I don’t know how to read music so maybe a musically-literate reader can help me out): https://www.youtube.com/watch?v=gCL5Zvnt0TU
A couple centuries later—you can hear and see the different lines of music played here, in Khachaturian’s gorgeous adagio from Spartacus (this piece brings me to tears every time): https://www.youtube.com/watch?v=wXsDsLHasWo
Here’s what 20th-century New York City sounded like. This is a 1940s Hollywood recreation of the 1924 debut of George Gershwin’s Rhapsody in Blue, but that sure looks like Paul Whiteman at the podium. The piano plays the main tune; the orchestra plays the variations. https://www.youtube.com/watch?v=VAuTouBhN5k
Back to the beginning of The Western Civ User’s Guide to Reading & Writing.