Question: The Toccata and Fugue in D minor, BWV 538, is an organ piece by Johann Sebastian Bach, like the better-known BWV 565, the Toccata and Fugue in D minor, BWV 565, is a piece of organ music written, according to its oldest extant sources, by who?
Sentence (from "Toccata and Fugue in D minor, BWV 538"): Like the better-known BWV 565, BWV 538 also bears the title "Toccata and Fugue in D Minor", although it is often referred to by the nickname Dorian – a reference to the fact that the piece is written without a key signature – a notation that is uncommon today and leads one to assume the Dorian mode.
Relevant evidence: No