Horns emulates several brass sections and a number of individual brass instruments.
Volume slider: Sets the overall volume level of the instrument.
Filter Cutoff slider: Allows less sound through at low values and more at high values—damping the sound or making it brighter.
Attack slider: Makes the sound start faster or slower. A fast setting makes it sound like striking a piano key, whereas a slow setting makes it sound like bowing a violin string.
Release slider: Determines the time it takes for notes to fade out after you let go of the keys on your keyboard.