Question: Unser Mund sei voll Lachens is a church cantata by a composer born in what year?
Sentence (from "Gelobet sei der Herr, mein Gott, BWV 129"): Rediscovery of the printed libretto of the cantata in the first decade of the 21st century led to a re-appraisal of prior assumptions regarding the early performance chronology of a few cantatas, including this one.
Relevant evidence: No