Martin Luther
- Frank Manheim biography in the Classical Composers Database focuses on how the reformer revolutionized church music in the 16th century.
- http://www.classical-composers.org/comp/luther

Did Luther use a drinking song as the basis for (A Mighty Fortress Is Our God)?
- FAQ including explanation of the term "bar form".
- http://www.ctsfw.edu/library/faq.php

Christian Singers of Germany: Martin Luther
- Chapter 5 of the book by Catherine Winkworth: includes biography and several translated hymns.
- http://www.ccel.org/ccel/winkworth/singers.c5.html

Martin Luther Collection: Sammlung
- Complete text of his hymns in English and German with a short biography.
- http://www.musicanet.org/robokopp/luther.html

The Musical Reforms of Martin Luther
- Shows the reformer's rationale in crafting a distinctly evangelical form of the Divine Service, giving insight into his role as compiler and composer of music with special emphasis on the Deutsche Messe. Includes MIDI audio files.
- http://www.carolinaclassical.com/articles/luther.html

Deutsche Geistliche Lieder
- Etext of German hymns, with English translation.
- http://www.worldwideschool.org/library/books/relg/christiantheology/DrMartinLuthersDeutscheGeistlicheLieder/toc.html

Selected Hymns of Martin Luther
- Project Wittenberg archive with English translations and some texts in the original German. Two English versions of A Mighty Fortress are included.
- http://www.iclnet.org/pub/resources/text/wittenberg/wittenberg-luther.html#sw-hymn

The German Mass and Order of Divine Service
- The 1911 translation of the 1526 Deutsche Messe with preface from the reformer, telling why he wrote it, its intended use, and various other rites and options for worship.
- http://history.hanover.edu/texts/luthserv.html