What ornamentation technique in the late Baroque involves adding a non-chord tone that is immediately released?

The ornamentation technique in the late Baroque that involves adding a non-chord tone that is immediately released is the acciaccatura. This ornament is characterized by its quick execution, often played as a very brief note that embellishes a principal note. The acciaccatura typically appears before the main note, creating a dissonant effect that resolves quickly into the consonance of the melody. This technique helps to add expressiveness and decoration to the melodic line.

While a trill also involves non-chord tones, it consists of quickly alternating between two adjacent notes, creating a different effect. A grace note serves a similar purpose as the acciaccatura, but it is usually played slightly longer and may not be exclusively released immediately. A fermata, on the other hand, indicates a pause or hold on a note or chord rather than an embellishment. Thus, the acciaccatura specifically fits the description of an ornament that is short-lived and swiftly released.