Accompaniment (noun)

A thing that goes with or complements something else; a secondary or supporting element.

Origin:

From latin accompanimentum, from accompaniare to go with.

Examples:

1. The piano was the perfect accompaniment to her singing.
2. The soup was served with bread as an accompaniment.
3. The orchestra provided accompaniment for the ballet.
4. The background music was a nice accompaniment to the dinner.
5. The wine was a perfect accompaniment to the meal.