Watch the Shuffle E Solo online guitar lesson by Jeff McErlain from Essentials: Advanced Blues Soloing
The point of this course is to start to crack the code of playing on the chord changes as opposed to over them. There's that lingo again! Playing over the core progression means we are playing one scale over everything, in a blues this often works out very well by just playing the minor pentatonic scale. The next level is playing on the chord progression, where we play the notes at a specific time on a specific cord. Good blues guitar playing does this in my mind, as it can add a level of sophistication to your playing. It takes time to know the right notes to play, but it is well worth the effort. A good way to do it is exactly what we're doing here - learn the solos that I've constructed and then break them down and analyze the placement of each note.