M-Audio Keystation 49MK3 - Compact Key USB-Powered MIDI Keyboard Controller with. Alesis V49 Key USB MIDI Keyboard Controller with 8 Backlit Pads, 4 Assignable Knobs and. Portable 32 Key USB MIDI Keyboard Controller with Eight Trigger Pads,. M-Audio pioneered the portable MIDI controller market with the Oxygen series of keyboard controllers. Today, M-Audio continues to be a leader of this technology by developing intuitive controllers for software-based music production and performance. The Oxygen 25 MIDI controller. Portable and total control over software and music creation - you and M-Audio Oxygen make a powerful combo.