For SATB Choir (accompaniment optional). Just a wonderful polyphonic setting of the tune Nun komm der Heiden Heiland by an early Renaissance composer. And really, how can you not love someone named Balthasar? Just one stanza, but a great introit for Advent, an Advent evensong, or Advent compline. It's short - under a minute - but even as a short anthem this one will work.
Savior of the nations, come,
virgin's Son, make here thy home!
Marvel now, O heaven and earth,
that the Lord chose such a birth.