Cantata 140 is one of Bach's most famous and beloved sacred cantatas. Based on the late-sixteenth-century hymn composed by Phillip Nicolai, Sleepers Wake is the subjectof three of the cantata's seven movements. Originally arranged for two altos and bass flute, alternate C flute and alto parts are included as well, allowing for aperformance by almost any combination of flutes. It is particularly effective when performed as a choir piece featuring the lower pitched flutes. Sleepers Wake is oftenassociated with Christmas performances, but this well-recognized work can be enjoyed at any occasion.