GarageBand Tuned Percussion
The Tuned Percussion sound is sample based. It emulates a vibraphone, xylophone, timpani, steel drums, and other tuned percussion instruments.
Volume slider: Sets the overall volume level of the instrument.
Filter Cutoff slider: Allows more (high) or less (low) of the sound through, making it brighter or damping it.
Release slider: Determines the time it takes for notes to fade out after you let go of the keys on your keyboard.