Watch the Love the Overtones online guitar lesson by Jeff McErlain from 50 Blues Guitar Licks You MUST Know
The term overtone generally refers to a specific set of frequency components that appear above a musical tone. Got that? A note without overtones sounds like a beep you hear in a hearing test or a test pattern on a TV. Not very pleasant. All acoustic instruments produce overtones. On guitar they are especially noticeable when you play two or more notes at a time, add in some gain and they really go crazy. That's what makes this lick so nasty sounding.