Some pastorales have a rural subject, while others use familiar musical themes to evoke this feeling. A true pastorale is a simple opera that takes place in the countryside or on a farm. Other musical pastorales recall earlier forms of music and tend to be very slow, with droning bass notes. Baroque pastorales include parts of Handel's "Messiah" and a piece by Bach called "Pastorale." The word comes from pastoral, originally "pertaining to shepherds," from the Latin pastoralis, "of herdsmen."