A discordant murmuration was heard among the crowd.

a:

being at variance, disagreeing, as ‘discordants opinions’; b: quarrelsome as ‘a discordant family’
murmuration:

the

utterance of low continuous sounds or complaining noises, ‘the murmuration of the crowds’ — A. E. Richardson; ‘ceaseless, inarticulate murmuration of prayer’ — Frederic Prokosch (Merriam-Webster)