Expression
Articulation
The way a note begins, continues, and ends.
In plain English
Articulation describes whether notes are short, smooth, detached, forceful, gentle, or connected. It is about how you play a note, not which note you play.
Try or listen for this
The same four notes can sound playful when short and detached, or calm when smoothly connected.
Why it matters
Articulation gives a musical line character and helps an ensemble play with a shared sound.