MU MIDI Controller for Mac

From Music Unfolding:

Music Unfolding MIDI Controller is a software MIDI controller. Use it to play synthesizers and enter music into music notation programs. It uses a combination of mouse, keyboard, and optionally a Wacom Tablet, to send messages to attached MIDI devices. MU MIDI Controller works with both software and hardware MIDI devices.

• Configurable keystroke and mouse control parameters for single notes or chords.
• Contains extensive list of predefined chords or edit your own.
• Chords and single notes can be sent to separate MIDI channels.
• Controls a variety of MIDI parameters, including note velocity, pitch bend, aftertouch, breath control, and modulation wheel. These can be controlled with the mouse, keyboard keys or pen x,y tilt and pen pressure.
• Includes controls for volume, balance, pan, legato, and portamento.
• Includes basic interface for bank and program change messages.
• Define and save an unlimited number of controller configurations.
• Controller configurations can be built to emulate different instruments. Controllers can also be set up to conveniently play specific songs.
• Includes utility for note name to MIDI note number conversion.