Adóro Te Devóte is an ancient Eucharistic hymn of the Catholic Church. The well-known melody was originally composed as a Gregorian chant for a Latin text written by St. Thomas Aquinas. The melody has also been used for other more contemporary texts, including For the Beauty of the Earth.
This is an instrumental piano arrangement of the chant melody. It is somewhat unusual in that it has no time signature — instead, it tries to stay very true to the unmetered Gregorian interpretation. Phrases are delimited with various shades of pauses: tick marks, half, full, and double barlines. Harmonically, however, the piece is very modern. It should be played freely, as though it were a chant, a series of pitches that sound and reverberate outside of time.
The first two (translated) verses of the hymn, though unsung in this arrangement, speak to the meaning of the piece:
Prostrate I adore Thee, Deity unseen,
Who Thy glory hidest 'neath these shadows mean;
Lo, to Thee surrendered, my whole heart is bowed,
Tranced as it beholds Thee, shrined within the cloud.
Taste, and touch, and vision, to discern Thee fail;
Faith, that comes by hearing, pierces through the veil.
I believe whate'er the Son of God hath told;
What the Truth hath spoken, that for truth I hold.
Just for fun, here's how this piece looks with my synesthesia applied: