›[I or T]to change the style, loudness, etc. of something such as your voice in order to achieve an effect or express an emotion: His gentle introductory tone modulates into a football coach's pre-game pep talk.ChangingAdapting and modifying Adapting and attuning to somethingChanging frequently›[I]specializedto change from one musical key to another: Here we modulate from G major to A minor.modulation