Open English Wordnet
Nouns
(n)accompaniment, concomitant, attendant, co-occurrencean event or situation that happens at the same time as or in connection with another
(n)accompaniment, musical accompaniment, backup, supporta musical part (vocal or instrumental) that supports or provides background for other musical parts
(n)complement, accompanimentsomething added to complete or embellish or make perfect“a fine wine is a perfect complement to the dinner”, “wild rice was served as an accompaniment to the main dish”