Much of Kuhnau's vocal music is lost, including an opera ("Orpheus"), a setting of the Passion according to St. Mark ("Markus-Passion"), a three-choir "Te Deum", and at least two settings of the mass. The surviving cantatas are simple harmonically and melodically, yet expressive. Unlike those of his predecessors at the Thomaskirche, Kuhnau's cantatas feature a unified approach to form: most begin with an instrumental section followed by alteration of arias and recitatives. The Christmas cantata "Uns ist ein Kind geboren", formerly attributed to Bach as BWV 142, was most likely composed by Kuhnau.