← CLR MIDI Monitor

Quick guide

CLR MIDI Monitor

Version 1.0.2 · macOS 13 or later · Apple Silicon

Start monitoring

  1. Open CLR MIDI Monitor and click Options to show the sidebar.
  2. Select the MIDI inputs you want to inspect. All selects or clears listed ports; Refresh updates the list.
  3. Switch Monitoring on. Play a controller or start MIDI playback.
  4. Read the latest event above History. Click a history row to inspect its details.

Observe an app sending MIDI to hardware

Select the hardware destination under Outputs, then turn Monitoring on. Keep the sending app’s normal routing. OUT identifies the destination port, not the sending app. The bundled output observer is prepared automatically. If its status requests a restart, restart the Mac once; the monitor does not force a CoreMIDI restart.

Receive MIDI directly from software

Enable Receive from software and Monitoring. In your music app, choose CLR MIDI Monitor — Receive as that app’s MIDI output. In Ableton Live, enable Track for this output in MIDI settings and select it in the MIDI track’s MIDI To menu. Sending directly to the monitor replaces that track’s hardware destination; use Outputs observation when you want to keep the hardware routing.

Make events easier to read

Choose controller and note names or decimal numbers. For note names, choose Middle C = C3 or C4. Display filters can hide voice messages, System Common, SysEx, Clock and Active Sensing. Search narrows the visible list. Filters affect the display, not the exported capture.

Stop and export

Turn Monitoring off to stop capture; the red OFF overlay marks the stopped history. File → Export Capture saves retained events as JSON, including hidden events. Export before quitting: history is held in memory and capped at 10,000 events. Clear removes retained history. Multiple windows share one session; the app prevents a second independent instance.

If nothing appears

Check Monitoring, selected ports, display filters and the sending app’s output routing. Click Refresh after connecting hardware. For output observation, read the output status. MIDI kept entirely inside a DAW or plug-in may not appear on CoreMIDI ports.

CLR website shortcut

Click the CLR logo to open the Custom Live Rigs website. Right-click the logo to copy the address. If macOS cannot open the link, the app copies the address and displays a notice.

Compatibility and limits

Native Apple Silicon macOS app; no Intel or Windows build. No MIDI send, echo or thru functionality. MIDI 2.0 semantic decoding and complete SysEx reassembly are not implemented; raw UMP and fragments remain inspectable. Capture has finite capacity; drop counters report overload.

Install on macOS

  1. Download CLR MIDI Monitor from the official CLR release page, unzip it and move CLR MIDI Monitor.app to Applications.
  2. Open it once from Applications. If macOS blocks it because it cannot verify the developer, close the alert.
  3. If—and only if—you trust this download, open System Settings → Privacy & Security, scroll to Security, choose Open Anyway for CLR MIDI Monitor and confirm the next prompt.
  4. Open the app again. This approves only this app; do not disable Gatekeeper globally.

License and security. Free for noncommercial use under PolyForm Noncommercial 1.0.0. Commercial use requires separate permission. This build is not signed with a CLR Apple Developer ID and is not notarized. macOS may warn or block it; the manual approval above is not Apple verification. Download only from the official CLR release page. See Apple’s instructions for safely opening Mac apps.