GOAL:
 To provide a deep hands-on dive into the mystery of how waves traveling on a string attached to a wood box makes sound.  We expand to epic scale a common instrument to see and feel the physics of materials interacting and discover the joy and limitations of what it means to hear.

SOUND:
Escalier Forte can produce an extreme range of frequencies - particularly at the low end of the spectrum going well below 1 hz.   Each string is “tuned” to a different tension from highest (red) to lowest (blue). For humans, with a limited perception to low frequency, this is appreciated as a visual experience of colored strings beautifully oscillating with each other.  Fretting a string - holding it with one hand and plucking with the other hand -  roughly 12 feet above the saddle produces sound audible to humans.  For humans, audible sound literally comes into existence moving down the string into the human hearing range.  The large wood resonator and nylon weave strings give the sound the warmth of a very deep orchestral bass instrument.  The massive stairwell acts as both a secondary resonator at a reverberant chamber.

MATERIALS:
Five 125 foot lengths of paracord 
Baltic birch and hickory plywood 
Steel saddle anchors into cement floor and steel stair girder 
Redwood Saddles with steel

STRINGS:
The strings are a common lightweight nylon rope originally used in the suspension lines of parachutes. This cord is now used as a general-purpose utility cord. This versatile cord was used by astronauts during the 82nd Space Shuttle mission to repair the Hubble Space Telescope. 

THE RESONATOR:
The front and back soundboard are made of Baltic Birch plywood.  Baltic birch is among the most sought-after wood in the manufacture of speaker cabinets. Birch has a natural and balanced resonance that supports high and low frequencies.  The sides are made of hickory plywood. 

TECHNIQUE:
Climbing the staircase, play any string anywhere. Many people can play at once.  The instrument makes tonal and percussive sounds on the strings.  The instrument produces sound from the resonator body at the bottom of the stairs. 

SCIENCE:
Escalier Forte slows down the phenomena of a wave to a scale humans can appreciate visually.  At 1 hertz, or one swing  of a string side to side in one second, an impulse of the pluck is seen traveling up and down the string quickly. a slower wave is produced thereafter, and smaller waves are then visible rippling on top of the slower wave.  In physics EF demonstrates disturbance, elasticity, and amplitude among many many other things.  In musical terms, we see the transient, fundamental, harmonics and timbre of a 'note'.  Wave motion is fundament to all physics and therefor the universe around us.