The UMX61 from Behringer is a velocity sensitive 61-key USB/MIDI keyboard controller, that can function within a computer based audio set-up, or stand-alone.
In addition to ten programmable MIDI controllers and eight user-set buttons for outputting switch control messages, the UMX61 ships with audio/MIDI software from Ableton, along with fifty virtual instruments.
A USB/Audio interface is also included and the controller can be powered via the USB bus, or by batteries or an external power supply (batteries and power supply not included.)