To get MIDI data into Logic, the Environment must have a Physical Input cabled to a Sequencer Input.
To make things easier to find, Logic's Environment is organized into layers holding similar Objects.
Standard Instrument Objects point to mono-timbral MIDI devices that use only one MIDI channel.
Multi Instrument Objects point to multi-timbral MIDI devices that use up to 16 MIDI channels. The buttons on the Multi Instrument's surface represent each of the 16 available subchannels.
By using the Instrument Object's Program parameter to select instrument sounds, you ensure that the correct synthesizer programs are saved with your song and then properly recalled every time the song is opened.
The Autoload Song contains customized Instrument Objects that reflect the setup of your personal studio.
For Logic to recognize the Autoload Song, it must be saved in the User > Library > Application Support > Logic > Song Templates folder.