In 17th-century philosophy, the movement of the stars creates a perfect Music of the Spheres, which is reflected in the harmonious nature of the Human body, and imitated in actual music, played or sung.
This is a hierarchical connection, with heaven at the highest level. Human-beings are a microcosm, the cosmos reflected in minature. Musical performance imitates the perfect movement of the cosmos.
The movement of the stars also defines Time, which is measured in musical notation, perceived as the feeling of tempo and the quality of movement, and indicated by the beat of the Tactus-hand. [All of these were far more precise than period clocks.]
Again, there is a hierarchical connection with heavenly time at the highest and slowest level of years (Sun), months (Moon), days (Earth). Embodied time (pulse, heartbeat and the Tactus-hand) imitates cosmic perfection at a human level of seconds. Music sub-divides this time into even shorter durations, faster movement.
Musical notation – i.e. Measure – is calibrated to real-world Time at the level of the Tactus-Beat (Zacconi 1596). Tempo literally means Time – not the ‘speed’ of a performance, but the duration in real-world Time of a Measure. In this philosophy, musical Time imitates the constancy of cosmic Time.
There is a gradual change during the 17th & 18th centuries from this Renaissance concept (that musical notation is a representation of real-world Time, defined by the cosmos) towards the modern assumption that Tempo is subjective, a perception of speed. Another modern assumption takes hold in the 19th century, that performers can choose their own speed, even vary the speed from bar to bar.
MOVEMENT & SOUL
Baroque Time is not Newton’s Absolute Time, “like an ever-rolling stream”, it is Aristotle’s “time as a number of motion”. In Aristotle’s Physics, this movement (and therefore, Time itself) can only be perceived by a Soul.
When Baroque writers call Time “the Soul of Music”, they mean that Time gives the dry numbers of musical-notation meaning in the real world, transforming them into living sound, what we would call ‘live Music’.
LIFE, MOVEMENT & PASSIONS
Music seeks to ‘move the Passions’, to sway emotions, which are ‘the affections of the Soul’, Affekt (German), affetti (Italian). The effects of soul-musical emotions are felt in the mind and in the body.
17th-century Pneuma, mystic breath, is the divine energy giving the breath of life (from heaven), and also the networked energy connecting mind, body and soul (human, rather like oriental Qi), and also the artistic Energia that communicates between musician and listener (in performance). This is the same hierarchy as in Music.
Perfect heavenly Movement creates Time, which gives life to Music, which moves the Passions. Perfect heavenly Movement also creates Music. The heavens are turned, and the human soul created, by the Divine Hand. These relations are causal: one creates another.
If you keep this in mind, whilst you move your hand in the embodied time of Tactus, you may feel something of the baroque Spirit of Music, maintaining a constant connection to cosmic Time, Music & Pneuma in order to communicate every-changing Passions to listeners.
This connection is also causal and embodied. It’s not enough to think about it, you also have to beat Tactus, otherwise it won’t happen.