Last time we tracked an electric guitar in Garageband, using the on-board amps and effects. Today we'll put down some acoustic guitar, with as natural a sound as we can get. I'm going to plug in a Gibson J-45 with a Fishman Natural Matrix pickup in it.
The first step is to click on "Track" in the toolbar and select "New Track"...or simply press "Command", "Option" ,"N" as a shortcut. This gives us the prompt to choose from three different kinds of tracks - "Software Instrument", "Real Instrument" or "Electric Guitar" (Fig. 1). We'll chose 'Real Instrument", even though we are plugging in because we want the straight sound of the guitar without the amps and effects options of the Electric Guitar track. If we were using a microphone to record the acoustic, we would also use the "Real Instrument" track.
This creates a generic blank track that is titled "No Effects" by default (Fig. 2). We can slide over to the info pane (if it is not open, "click the "i" button at the bottom right of your screen).