MIDI Clock

MIDI Clock Output

The MIDI Clock destination sends a standard MIDI clock signal based on the BPM of the currently playing track. Any hardware or software that can sync to an external MIDI clock (synthesizers, drum machines, lighting controllers, visual software) will lock to the tempo of your track automatically without you needing to tap tempo or manually adjust anything.

This is particularly useful for live performers and hybrid DJs who want external hardware or visual software to stay rhythmically in time with their mix.

How MIDI Clock Works

MIDI clock is a continuous stream of timing pulses transmitted over a MIDI connection. The standard rate is 24 pulses per quarter note (PPQN), meaning 24 clock messages are sent for every beat. At 120 BPM, that is 48 clock messages per second. At 140 BPM, that is 56 per second.

When a track starts playing, Now Playing reads its BPM value and begins transmitting MIDI clock pulses at the corresponding rate. When the track changes to a new BPM, the clock rate updates to match. The clock runs continuously as long as the destination is enabled and a track is active.

Now Playing also sends MIDI Start (0xFA) and MIDI Stop (0xFC) messages to signal when playback begins and ends, which allows receiving devices to align their sequencers to the beginning of a bar rather than jumping in mid-phrase.

Note

MIDI Clock carries tempo information only. It does not transmit note data, program changes, or song position pointer (SPP) messages. Devices that need song position information to lock to a specific bar will not receive that from this destination. Check your gear’s documentation to confirm it can sync tempo from an external MIDI clock source.

What You’ll Need

• A way to receive the MIDI clock output from your computer. This can be:
  • A physical MIDI interface connected via USB (such as an iConnectivity interface, Roland UM-ONE, or similar) with a standard 5-pin DIN MIDI cable going to your gear.
  • A USB MIDI device that appears as a MIDI port in your operating system.
  • Any software on the same computer that accepts MIDI clock input via a virtual MIDI port (on macOS this works out of the box; on Windows, see the platform notes below).

Platform Notes

• macOS: No extra setup needed. Now Playing creates a virtual MIDI port named Now Playing Clock automatically when MIDI Clock is enabled.
• Windows: Requires Windows 11 with Windows MIDI Services installed. A virtual MIDI port is not created natively; you must create a port named Now Playing Clock in loopMIDI first, then enable MIDI Clock in Now Playing.
• Windows 10: Not supported.

Setup

1. macOS: No extra steps needed before enabling. Windows: Open loopMIDI, create a port named Now Playing Clock, and ensure it is active.
2. Open the Now Playing dashboard and go to Settings → Destinations → MIDI Clock.
3. Toggle Enable MIDI Clock Output on.
4. Optionally configure the BPM Source and Fallback BPM (see below).
5. Click Save Settings.

The clock will begin transmitting the next time a track plays.

Compatible Devices and Software

Any device or application that accepts standard MIDI clock sync will work. Common examples:

Hardware

• Synthesizers with MIDI sync input (Roland, Korg, Moog, Arturia, Dave Smith, and most others)
• Drum machines and step sequencers (Roland TR-series, Elektron, Teenage Engineering)
• Hardware effects units with tempo-syncable parameters
• Eurorack MIDI-to-CV converters for syncing modular synthesizers

Lighting and Visuals

• Resolume Arena and Avenue (MIDI clock input for BPM sync)
• ENTTEC lighting controllers with MIDI input
• MadMapper and similar VJ software
• TouchDesigner (via MIDI input component)

Software DAWs and Tools

• Ableton Live (set it to sync to external MIDI clock)
• Logic Pro (MIDI sync settings in Project Settings → Synchronization)
• VCV Rack (via MIDI-CV module)

Receiving MIDI Clock in Your Device

The exact steps depend on your gear, but the general process is:

1. Connect the MIDI clock output from your computer (via interface or USB) to the MIDI In of your gear.
2. In your gear’s settings, find the sync or clock source option and set it to External MIDI Clock or MIDI Sync.
3. Disable the gear’s internal clock if required (some devices do this automatically when external sync is detected).
4. Start a track in Now Playing. The gear should lock to the incoming tempo.

For software like Ableton Live: go to Preferences → Link, Tempo & MIDI, find your MIDI input port in the MIDI Ports list, and enable Sync for that port.

Troubleshooting

MIDI Clock output is not working on Windows

• Confirm you are running Windows 11 with Windows MIDI Services installed. Windows 10 is not supported.
• Confirm loopMIDI is running and has a port named Now Playing Clock.
• If the port name does not match exactly, Now Playing cannot find it. Check the name in loopMIDI and ensure it reads Now Playing Clock.

Connected gear is not syncing to the clock

• Verify the receiving device is configured to use external MIDI clock as its sync source, not its internal clock. This is often a menu setting called “Sync Source”, “MIDI Sync”, or “External Clock.”
• Confirm the physical MIDI connection is correct: clock output from Now Playing’s interface goes to the MIDI In port on your gear (not MIDI Out or MIDI Thru).
• Check that the MIDI cable is fully seated and functioning. Try a different cable if available.

Clock drift (gear falls slightly out of time)

Clock drift is typically caused by USB latency or driver issues rather than Now Playing itself. Try:

• Using a dedicated USB MIDI interface rather than a generic or built-in audio interface.
• Connecting the interface directly to a USB port on your computer rather than through a hub.
• On Windows, installing ASIO drivers for your interface if available, which can reduce system-level latency.

BPM is correct but gear plays at half or double speed

Some devices interpret MIDI clock differently. If your gear plays at half speed, it may be set to 48 PPQN mode; at double speed, it may be set to 12 PPQN. Check your gear’s MIDI clock resolution or PPQN setting and set it to 24 PPQN to match the MIDI standard that Now Playing outputs.