accompaniment

noun

1.
an event or situation that happens at the same time as or in connection with another
attendant concomitant co-occurrence
Derived from:
accompany
2.
a musical part (vocal or instrumental) that supports or provides background for other musical parts
backup musical accompaniment support
Derived from:
accompany
3.
something added to complete or embellish or make perfect
togive complement
4.
the act of accompanying someone or something in order to protect them
escort
Derived from:
accompany