A Song of Redemption Angels Can't Sing

My brothers pray for their victims
     singing a harpists' new song
a new hymn before the throne,
    before mankind, before God,
before the four living creatures,
     and before the elders.

They sing a hymn not learned
    by all except by those
following the Lamb.  They
   are the ransomed, forgiven,
absolved, and have the Father's
  name written on their foreheads.

h/t The Preacher Poets, 4th Annual OPrize p. 91