Because of its portability, the acoustic guitar can be wonderful songwriting device. However, having a pocket symphony in your head–or pocket, as it were–does you little good if your hands aren't on board. Fortunately, YouTube user Sawlon is here to help you train your head and hands with his series of free video guitar lessons. In this installment, you'll learn how to modify major barre chords on acoustic guitar to obtain different chord types (e.g., minor and m7). Remember, the more you practice and the more theory you know, the better you'll sound and the better able you'll be to play what you hear. To learn how to easily add a number of chords to your own repertoire, take a look!