You won't find a better opportunity to acquaint yourself with the hymns and songs of Martin Luther than this.
This monumental recording project presents, for the first time, a complete recording of all the hymns, ballads, and chants composed or authored by Martin Luther. This four-CD set provides numerous vocal and instrumental settings combining Renaissance, Baroque, and modern instruments.
The CD retails for $44.95 (on sale now for $34.95 unless I am mistaken), so this is a great deal. If you click the link above, you'll be taken directly to Amazon's page for this recording.