Hey guys and gals, I would love if someone could settle this question for me once and for all. I've got a 13" white unibody late 2009 Macbook (not pro) running OS X 10.6.8. I'm attempting to plug my electric guitar into the headphone jack using a 1/4" to 1/8" adapter and play it through Garageband. Now, I'm a drummer, so even this insanely basic recording setup is foreign to me. I've gone into System Preferences>Sound and set the input to "Sound Input" so that I'm using "Audio Line-In Port". In Garageband, I've gone into Preferences and set the input and output to "Built-in input" and "Built-in output". I've got the monitor set to "On" and the input source to "Mono 1". And yet I've got no indication that I'm getting a signal. Why doesn't this work? The guitar works when I tested it on my amp, so it's not the cables or the guitar. I've seen some rumors floating around that this line-in on this mac may not work without some kind of amplification between the guitar and the laptop. Is this true? Any help would be much appreciated.