Watch the Sweet Intro online guitar lesson by Jeff McErlain from Solo Factory: Chicago Blues
Here is a classic blues intro borrowed from Matt Guitar Murphy from his into to the Robert Johnson classic "Sweet Home Chicago". I got this from one of my favorite movies of all time "The Blues Brothers", if you didn't know, the band in that film is made up of cream of the crop with members like Steve Cropper, Matt Guitar Murphy, Donald Duck Dunn, and others. The lick is a classic intro that can be used at the beginning of many different feels and grooves. Experiment!