How Novation Launchpad Uses MIDI Notes and CC Messages

The Novation Launchpad controls software like Ableton Live by functioning as a specialized MIDI controller that translates tactile button presses into standard MIDI Note and Control Change (CC) messages. This article explains the underlying communication protocol between the Launchpad and digital audio workstations (DAWs), covering how Note-On messages trigger audio clips, how CC messages handle session navigation and scene controls, and how bidirectional MIDI data provides real-time LED visual feedback.

The 8x8 Grid and MIDI Note Messages

The core of the Launchpad is an 8x8 matrix of 64 pads primarily mapped to MIDI Note messages. Each physical pad corresponds to a unique MIDI note number across a designated MIDI channel.

When you press a pad to launch a clip loop:

1. Note-On Event: Pressing the pad transmits a Note-On command containing the specific note pitch assigned to that slot, along with a velocity value (typically 127).
2. DAW Clip Assignment: The DAW interprets this incoming Note-On message as a trigger command for the corresponding clip slot in the Session View.
3. Quantized Launching: Rather than playing the clip instantly, the DAW checks its global quantization settings (e.g., 1 bar). The loop enters a queued state and begins playing precisely on the next quantization boundary.
4. Note-Off Event: Releasing the pad sends a Note-Off message (or a Note-On with a velocity of 0). In standard clip-launch mode, the DAW ignores the release event, allowing the loop to play continuously. In "momentary" or "gate" launch modes, the DAW stops playback the moment the Note-Off command is received.

Control Change (CC) Messages for Navigation and System Modes

While the primary 64-pad grid relies on MIDI Notes to target specific audio loops, the top and side function buttons frequently utilize MIDI Control Change (CC) messages to manage the operational state of the session.

• Top Function Buttons: On most Launchpad models, the top row of round buttons sends CC messages (typically CC 104 through CC 111). These messages control mixer modes, directional session scrolling, and track arming.
• Value-Based Execution: Unlike note pitches, CC messages consist of a controller number and a parameter value ranging from 0 to 127. A button press typically sends a value of 127 (activating a mode or shifting the grid window), while a release sends a value of 0.
• Scene Launching: Depending on the firmware mode (such as Programmer Mode versus Live Mode), the rightmost column of buttons may transmit either specific CC messages or high-register MIDI Notes to trigger entire rows of clips simultaneously (Scene Launch).

Bidirectional MIDI and LED Feedback

The Launchpad's integration relies on two-way communication. Just as the controller sends MIDI data to the computer, the DAW transmits MIDI Note and CC data back to the Launchpad to update the RGB LEDs beneath the pads.

The visual status of a clip loop corresponds directly to the velocity value sent back by the DAW:

• Queued Clips: The DAW sends a alternating sequence of Note-On velocities corresponding to colors that flash in sync with the tempo, indicating that a clip is waiting for the next downbeat.
• Playing Clips: A static Note-On message with a specific velocity code lights the pad solid green, confirming that the loop is actively playing.
• Recording Loops: The DAW sends a velocity byte mapped to the color red to indicate overdubbing or active recording into an empty slot.
• Stopped Clips: When a clip is stopped, the DAW sends a low-intensity color velocity or a Note-Off command, dimming or disabling the LED.

By mapping musical triggers to MIDI Note values and interface commands to CC data, the Launchpad acts as an intuitive physical extension of software-based loop engines.