Guitar buttons not mapping

Hi all! I recently bought a Guitar Hero World Tour guitar (Red Octane, PS3) for my dad to play Clone Hero. Neither of us have ever played this game before, but he really liked Guitar Hero on the Wii. I installed the game on his Macbook and plugged in the dongle. The guitar appears to be connected because it blinks (though, to be honest, I'm not even sure if I'm pressing the right button to pair), and when I press the space bar within the game, it says that the guitar is connected to Player 1. But when I try to map the buttons, there's no input whatsoever no matter what button we press (including strum). Any help would be much appreciated!