MIDI of "Ut Queant Laxis", an 8th century hymn best known for being the basis for Ut-Re-Mi-Fa-Sol-La, later modified to the familiar Do-Re-Mi-Fa-Sol-La-Ti. Each line begins with a note that moves up the scale from Do to La (Ti not being used in music of that period).
Author: Paulus Diaconus (c. 720 – 799)