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 play alternating bass patterns in the key using open G, C, D, and Em chords on acoustic guitar. 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 get started playing alternating bass lines on your own guitar, take a look!