1APM [uncountable and countable]
music that is played in the background at the same time as another instrument or singer that plays or sings the main tune
piano/orchestral/organ/guitar etc accompaniment
He plays folk music with guitar accompaniment.
to the accompaniment of something
An elderly man puffed on a trumpet to the accompaniment of drums and piano.
something that is provided or used with something else:
White wine makes an excellent accompaniment to fish.
while something else is happening or while another sound can be heard:
to the accompaniment of somethingAPM
They were exercising to the accompaniment of cheerful music.
something that happens at the same time as another thing