Check the listing for details. Novation Launchkey 49 MK4 MIDI Controller. Condition: New. Listed at 279.99 USD. The Launchkey 49 includes sophisticated Chord and Scale modes, perfectly synced with the OLED display to keep you in key. It also features an editable Arpeggiator, three Chord Modes for quick musical progressions, and a Chord Detector that displays the current chord on the OLED screen.