"Lasst uns erfreuen herzlich sehr" (Let us rejoice most heartily) is a hymn tune that originated from Germany in 1623, and which found widespread popularity after The English Hymnal published a 1906 version in strong triple meter with new lyrics.

''Lasst uns erfreuen'' derives its opening line and several other melodic ideas from GENEVAN 68, which was initially published in a Lutheran service in 1525 as a setting for Psalm 119.

[2][3] The tune's first known appearance was in the 1623 hymnal Auserlesene, Catholische, Geistliche Kirchengesäng (Selected Catholic Spiritual Church-Songs) during the Counter-Reformation and the Thirty Years' War, and the oldest published version that still exists is from 1625.

[4] Below is the first verse from the original German (the 1625 publication, excluding the Alleluias), alongside a half-rhymed, line-by-line English translation that shares the same 88.88 "long meter":

The original hymn still appears in the main German-language Catholic hymnal Gotteslob, with slightly modernized text,[8][9] and the tune as well in the Protestant Evangelisches Gesangbuch (Nr.