"Old 100th" or "Old Hundredth" is a hymn tune in long metre, from the second edition of the Genevan Psalter. It is one of the best known melodies in many occidental Christian musical traditions. The tune is usually attributed to the French composer Louis Bourgeois.
The Old Hundredth metrical setting from a 1628 printing of the Sternhold and Hopkins Psalter.
The Genevan Psalter, also known as the Huguenot Psalter, is a 1539 metrical psalter in French created under the supervision of John Calvin for liturgical use by the Reformed churches of the city of Geneva in the sixteenth century.
First edition title page of the 1539 Strasburg Psalter