1)   GCH Guitar Academy course (Mac OSX) 3.00 This version includes a free tuner, a free metronome, an interactive chord chart (with sound) and four lessons. The lessons come complete with backings, video support and a printable PDF, so you can study what you are learning away from the computer. 2)   GCH Guitar Academy course (unit 1) 2.6 This version includes a free tuner, a free metronome, an interactive chord chart (with sound) and four lessons. The lessons come complete with backings, video support and a printable PDF, so you can study what you are learning away from the computer.