The phrase "are in unison" suggests that two or more things or people are acting together in harmony, agreement or consensus. Its antonyms could include: discordant, disagreement, disagreement, dissent, inharmonious, contradictory, conflicting, unfriendly, dissenting, non-unanimous or divided. These terms convey a sense of difference, disagreement or opposition, implying that there is a lack of alignment, coordination or mutual understanding among the parties involved. In many contexts, such as music, sports, politics or business, being in unison is considered a desirable outcome, whereas discord or dissent can create confusion, conflict or even failure.