Legato

Expression maps go a step further by mapping a controller like CC one or a dedicated expression pedal to an instrument's built-in dynamics controller, giving you real-time volume and vibrato control across the orchestra.

Legato, for example, isn't just a note that drips into the next.

It involves overlap timing, attack smoothing, and sometimes a special legato sample loop that extends across two or more notes.

In practice, I often set up my MIDI sequencer so that every string passage has a dedicated key switch for sustain, a second for staccato, and an expression track that follows the performer's velocity curve.