Multi Instrument Objects are designed to represent multi-timbral MIDI devices: devices that send and receive MIDI signals over many channels at once. Almost all modern synthesizers and samplers can do this, so unless you collect vintage synthesizers, this is the Instrument Object you'll use most while working with Logic.
To demonstrate how a Multi Instrument works, this exercise sets up a Novation Supernova, but feel free to use any multi-timbral synthesizer connected to your computer.
From the Environment's local menu bar, choose New > Multi Instrument. A Multi Instrument is created.
From the Environment's toolbox, select the Text tool.
On the Multi Instrument Object, click the Multi Instrument's name and type the name of the MIDI device this Object will transmit MIDI signals to, then press Return.
In the Object Parameter box, click and hold the word All (located directly to the right of the word Port), and select the MIDI port that this Multi Instrument will transmit MIDI data through.
In the Object Parameter box, click the Instrument icon and select a graphic to represent your instrument.
A dialog appears asking if you'd like to change the icon for all subchannels.
You will explore subchannels in the next exercise, so for now click Change.
Logic assigns the selected icon to the Multi Instrument and to all of its subchannels.
Multi-timbral instruments can use several MIDI channels at the same time. To give you access to those multiple channels, the Multi Instrument provides 16 small buttons representing its subchannels. Button 1 equals MIDI channel 1, button 2 equals MIDI channel 2, and so on.
In the Object Parameter box, you'll notice the instrument's Channel parameter is currently set to All. Leave this setting untouched. With the Channel parameter set to All, this Multi Instrument will transmit on all 16 MIDI channelsbut in a very particular way: Subchannel 1 (button 1 on the Multi Instrument) transmits through MIDI channel 1 of the instrument's port, subchannel 2 transmits through MIDI channel 2 of the instrument's port, and so on.
From the toolbox, select the Arrow tool and click the subchannel buttons until you've enabled all the MIDI channels over which your multi-timbral MIDI device is able to receive MIDI signals.
Clicking a subchannel removes the strike through it and enables it. You can now select this subchannel from the Arrange window's Instrument List and assign it to a track.