anticipation
A non-chord tone that arrives early, sounding a note from the next chord before it has officially begun
In Depth
The anticipation is the opposite of a suspension: instead of holding back, the voice moves ahead to its destination before the harmony changes. It is almost always unaccented and approached by step, creating a brief moment of dissonance against the still-sounding previous chord. Anticipations are extremely common at cadences, where the melody lands on the tonic a beat before the final chord arrives, giving a sense of eager resolution.
The anticipation at a cadence is so ubiquitous in Classical music that most listeners do not even register it as a dissonance.