How to Handle Devices Connected with MIDI Thru Cables

The physical MIDI Thru connector of a MIDI device enables that device to forward MIDI performance data on to a second device, as illustrated here:

If you have physically configured your devices with MIDI Thru, then you probably want one device to play back MIDI received on certain channels, and the second device to play back MIDI received on other channels.

You will need to inform Composer about such a MIDI Thru configuration, so that Composer can correctly play back MIDI on the two devices. The following screenshot shows the part of Composer's MIDI Device Configuration Window that represents the above configuration:

The physical MIDI Out connector at the computer will be associated with an external output port, such as a "Creative SB Live! External MIDI".

2.	If the devices are not already included in the configuration, then add them using the New External Device command in the Device menu. For an introduction to adding a new device, see Configuring a New External MIDI Sound Module.

The new devices will be listed under a heading "Unassigned Device" at the bottom of the MIDI Device Configuration Window.

3.	In the MIDI Device Configuration Window, identify the external output port that corresponds to the physical MIDI Out connector, to which you have physically connected the first device. An external output port is listed in bold text, and has "Out" and "External Port" in the second and third columns.

If a placeholder device is already connected to that external output port, then disconnect it. A placeholder device has the same name as the MIDI output port to which it is connected. To disconnect the placeholder device, click its name to select it. Then choose the Disconnect From External Port command in the Device menu.

Click the name of the first device to be connected, in order to select it. (The order in which the two devices are connected or listed does not need to reflect how they are physically ordered with MIDI cables.) Then choose the Connect to External Port command in the Device menu. In the Connect External Device to Port dialog, select the external output port that you identified in step #3. For further details, see Connecting and Disconnecting Devices from an External Port.

Normally, when you connect two devices using MIDI Thru, you will want one device to play notes received on only certain MIDI channels, and the second device to play notes received on other MIDI channels. To do this, you will probably need to use either the front panel controls, or some software tool that accompanies your device, to "tune" the device to certain channels, and to have it ignore other channels.

For a given song, you can assign specific channels to each staff. For example, suppose you have tuned My Keyboard to channels 1 through 8, and My Sound Module to channels 9 through 16, using manual controls available on the two physical devices. Using the Staff Setup command in the Staff menu, you will need to assign channel numbers to the staves that are consistent with the devices to which they are assigned, as illustrated below:

If your external MIDI devices are capable of receiving MIDI program (sound) changes during playback, then Composer offers a more convenient means of assigning channels to the staves. You can "tune" the MIDI Thru devices to different channels using the manual controls available on the physical device. Then, in Composer, assign "Auto MIDI channel" to the staves. When a staff is assigned to an Auto(matic) MIDI channel, during playback Composer will pick any available channel to which that device is tuned. During playback, Composer might even reassign that staff to different channels at different times.

To tune Composer to the same channels as those which you have manually selected via controls on the external MIDI device:

2.	Click the device's channel buttons, which are arranged in four groups of four buttons, to toggle whether the channel is "tuned" or not. You can also drag the mouse over the channel buttons to toggle several at a time.

A green light indicates a channel to which the device is tuned. Untuned channels are indicated in gray.

Continuing with the above example, this is what the channel indicators look like when the first device is tuned to MIDI channels 1 through 8, and the second device to channels 9 through 16:

To assign staves to a MIDI Thru device without identifying the specific MIDI channel:

2.	For each staff, select the device in the Device column, and select "Auto" in the Channel column.

For more detailed instructions about assigning channels to staves, see Assigning MIDI Channels.