In which form is the voice accompanied only by the basso continuo?

The composer of this work is?

a) Tania León b) John Cage c) Arvo Pärt d) Milton Babbitt

What is the Geistliche Gesangbüchlein?

A) a collection of the most popular laude melodies and texts B) the nearly three hundred fifty motet-style compositions set all the Proper chants of the Mass for major feasts of the church year C) a collection a thirty-eight chorales and five motets D) a setting of the German Psalter in four-part harmony