Old Hundredth is a hymn tune in Long Meter from Pseaumes Octante Trois de David (1551) (the second edition of the Genevan Psalter) and is one of the best known melodies in all Christian musical traditions. The tune is usually attributed to the French composer Loys Bourgeois (c.1510 – c.1560). While first associated with Psalm 134 in the Genevan Psalter, the melody receives its current name from an association with the 100th Psalm, in a paraphrase by William Kethe entitled All People that on Earth do Dwell. Many other texts are also used with this melody, including a paraphrase of Psalm 117 by Isaac Watts as well as the text often referred to as the Doxology, written in 1674 by Thomas Ken, a clergyman in the Church of England:

Praise God, from Whom all blessings flow;
Praise Him, all creatures here below;
Praise Him above, ye heavenly host;
Praise Father, Son, and Holy Ghost.

A version was sung at the coronation of Queen Elizabeth II in 1953, with harmonization and arrangement by the composer Ralph Vaughan Williams.

See a list of other popular hymn and chorale themes here.

Videos:
Pierre Pincemaille: Improvisation sur “Noi canteremo gloria a Te” (aka OLD HUNDREDTH) – Chignolo d’Isola, Bergamo, Italy
Sietze de Vries – Improvisation on’The Old Hundredth’ – Martinikerk, Groningen