However, depending on the context, you could use several options:
General terms:
* Polyphonic: This refers to music with multiple independent melodic lines.
* Harmonized: This indicates that the music has added harmony, which is not present in plainchant.
* Non-Gregorian: This specifically excludes plainchant, which is often associated with Gregorian chant.
* Non-liturgical: This refers to music not used in religious services, as plainchant is primarily liturgical music.
* Secular: This indicates music not associated with religious settings or themes.
Specific terms depending on the context:
* Polyphony: For music with multiple melodies.
* Counterpoint: For music with multiple independent melodies that interact with each other.
* Homophony: For music with a single melody with chordal accompaniment.
* Opera: For staged musical works with singing and acting, which are typically more complex than plainchant.
* Symphony: For a large-scale instrumental work, which is obviously not plainchant.
Ultimately, the best word to use depends on the specific meaning you want to convey.