Luminescence

Luminescence is based on fragments from the melody Break Forth O Beauteous Heavenly Light, which was written by Johann Schop (ca. 1590–1664) and subsequently harmonized in several settings by Johann Sebastian Bach*. (It may enrich the overall musical experience, both for the ensemble and for the audience, to hear the original chorale before the piece is played.)

Break Forth O Beauteous Heavenly Light was first known as “Ermuntre dich, mein schwacher Geist” (Rouse thyself, my weak spirit), and was published in Lepzig in 1641 in Johann Rist’s Himmlische Lieder (Heavenly or Celestial Songs), where the tune appeared in triple meter along with text by Rist. Johann Sebastian Bach probably found an altered version of the tune in Johann Cruger’s Praxis Pietatis Melica (1647) and subsequently harmonized it in various settings. This particular setting is from the second cantata of his Christmas Oratorio from 1737.

The original melody had a different character in its original form, as it was more closely related to Renaissance musical style. By the time Bach harmonized the tune in the 18th century, musical preferences had shifted: the rhythm of the melody was made more consistent, the tempo became slower, and the harmony and counterpoint was more complex. This setting is still sung in modern churches at Christmas and is commonly known as Break Forth O Beauteous Heavenly Light.