  Noncommutative versions of theories with a gauge freedom define (when they
exist) consistent deformations of their commutative counterparts. General
aspects of Seiberg-Witten maps are discussed from this point of view. In
particular, the existence of the Seiberg-Witten maps for various noncommutative
theories is related to known cohomological theorems on the rigidity of the
gauge symmetries of the commutative versions. In technical terms, the
Seiberg-Witten maps define canonical transformations in the antibracket that
make the solutions of the master equation for the commutative and
noncommutative versions coincide in their antifield-dependent terms. As an
illustration, the on-shell reducible noncommutative Freedman-Townsend theory is
considered.
