The use of tones from one mode (mode here refers to the major and minor modes) in a passage that is predominantly in the other mode.
Borrowed Chords
Another term for mode mixture.
Mutation
Another term for mode mixture.
Picardy Third
When the tonic triad is "borrowed" from the major mode for use in minor. The Picardy Third was used to end most minor mode compositions in the early tonal era.
