How Music Works by Howard Goodall

You may find the “How Music Works” series (1: Melody, 2: Rhythm, 3: Harmony and 4: Bass) at http://www.youtube.com/user/timegrinder to be helpful. Though this series is not related to the harmonica, nor does it follow the same flow of the BluesHarmonica.com music theory lessons, watching the entire series… as well as any other series on the understanding of music… to be helpful in your understanding of common music theory elements. Thanks to jodanchudan for this recommendation.