Playback Channels in the MIDI Device Configuration Window

For each MIDI output device, internal and external, the MIDI Device Configuration Window displays 16 MIDI channel indicators, as illustrated here:

Many MIDI output devices are capable of simultaneously producing sounds for multiple instruments. During playback, each distinct instrument sound is produced by a different MIDI channel on that device.

If the MIDI Device Configuration Window is displayed at the same time a song is playing, you will see the playback channel indicators light up, indicating which channels are actively being used. For details about this feature, see Watching Device Activity While Playing a Song. Note that you can also observe overall note playing activity for a device in the Quick MIDI Device Configuration Window.

Some MIDI sound modules and keyboard synthesizers include the capability to tune into only certain MIDI channels among the 16 available. This capability is useful, for example, when the MIDI In connector of one device is connected via a MIDI cable to the MIDI Thru connector of another device. By default, both devices will redundantly play the same notes on any of the 16 channels. However, if you tune one device into some channels, and the other device to other channels, typically by using options on the front panels of these devices, then each device will only play on its assigned channels.

You can toggle whether a device is tuned into a particular channel by clicking the channel indicator or dragging the mouse over it. The following example shows two devices that are connected together via MIDI Thru. The first device is tuned to MIDI channels 1 through 8, and the second device to channels 9 through 16.

For further details about tuning devices to specific MIDI channels, see How to Handle Devices Connected with MIDI Thru Cables.