The following is a guest post from Archives Processing Technician Dr. Rachel McNellis.
In 2017 the National Aeronautics and Space Administration (NASA) provided the public with a soundtrack of “Spooky Space Sounds” for Halloween. Spacecraft had captured radio emissions from Jupiter, Saturn, and other cosmic bodies and transformed them into sound waves. NASA had captured sound from the universe! While this certainly was a fun discovery, the idea that planets produced sound was not new. Rather, the sixth-century philosopher Boethius proposed that the universe was a musical body—an idea that persisted throughout the Middle Ages.
A fifteenth-century collection of music theory treatises in the Music Division contains a diagram of the universe that can help us understand this thought process. It displays the cosmos as a set of concentric circles. The earth is at the center, and expanding outwards each circle is labeled with the name of the moon and six known planets: Mercury, Venus, the Sun, Mars, Jupiter, and Saturn, all of which rotate around the stationary earth. This is not far off from what modern science has discovered: the planets revolve around the sun in an elliptical motion. According to Boethius, however, these spheres rotate so quickly around each other that they produce a perfectly harmonious sound. It was inaudible to the human ear, although the ancient Greek mathematician Pythagoras had an idea.
According to a legend that is narrated in a treatise in this same manuscript collection, Pythagoras walked past a smithy and heard several blacksmiths flattening iron with five hammers of differing weights. The heavier hammers produced lower pitches and the hammers of lighter weight produced higher pitches. Marveling at their pure sounds, Pythagoras rushed home and stretched strings across a wooden board. The lengths of the strings were proportional to the weights of the between the hammers. As such, they produced the same pitches as the hammers, but with a perfectly consonant sound. These proportions must be the foundation of the universe—or so the theorists claimed. But how could this be? Boethius explained that the human body was also musical, and a mirror image of the cosmos. By performing music in perfect harmony, it was possible to hear an approximated sound of the universe.
Of course, such perfection is impossible to achieve, but theorists produced many instructional texts for teaching how to sing with great accuracy. In addition to two diagrams of the universe, this same manuscript volume contains three full-page drawings of a left hand with writing on each knuckle. These drawings helped singers to learn new melodies either by ear or from written notation. Now known as Guidonian hands, they are named after Guido of Arezzo, an eleventh-century monk and key figure in the development of music notation.
Guido invented the musical staff—the set of parallel lines and spaces that we use today when writing down traditional Western music notation. He also named notes using a series a syllables: Ut, Re, Mi, Fa, So, La. This may remind you of the song “Do-Re-Mi” from Richard Rodgers and Oscar Hammerstein’s musical The Sound of Music (1959) in which Maria teaches the Von Trapp children how to sing. Each line of its lyric begins with a one-syllable word, Doe, Ray, Me, Far, Sew, La, Tea, sung in order to the notes of the scale.
Guido, or more likely later theorists working under his name, created the hand diagram as a mnemonic device to make it easier to use these syllables, known as solfège, when singing a new piece of music. On the diagrams, the name of one or more syllables of a hexachord are written on each knuckle. Sometimes, the diagram would include a picture of the note written on the staff, as well. A singer would point to the correct knuckle for each pitch on their hand when singing a melody, which would help them visualize and, in turn, more quickly memorize the melody. So, if you need help with your singing, consult the Music Division’s digitized materials; several sources are ready to lend a hand.
Perusing other theory manuscripts in the collections may also surprise you with other illustrations that, like diagrams of the universe and the Guidonian hands, help us visualize and understand both medieval performance and instructional practices as well as the ways in which theorists understood music as more than notes on a page.
 “Spooky Space ‘Sounds,’” National Air and Space Administration, October 26, 2017, accessed July 12, 2021, https://www.nasa.gov/vision/universe/features/halloween_sounds.html
 Marchetto of Padua, Lucidarium
 Guido took these syllables from the first word of each line of text of the Roman Catholic hymn Ut queant laxis: Ut queant laxis / Re-sonare fibris / Mi-ra gestorum / Fa-muli tuorum / So-lve pollutis / La-bii reatum
 Other sources containing Guidonian hands include printed copies of the anonymous Tractatus musices, Gregorius Faber’s Mvsices practicæ erotematum libri II Mvsices practicae erotematum libri II and Gonçalo Martínez de Bizcargui’s Arte de canto Ilano y contrapunto y canto.