In the last lecture, I talked about that we need to communicate the groove we want when we count off a 12 bar blues. The groove is the feeling we wanted the music course, are known as shuffles is based on dividing every quarter note into triplet of eighth notes. Then you meet the middle eighth note in that triplet. The result is that the second eighth note you play is delayed a little bit. So, if you compare a straight A feel, that would be 1234. To a shuffle, the shuffle would sound something like one and three and four.
I think the shuffle has a nice feel to it. is very common in blues. So that's why I use it in this course. Just on a side note, please be aware of that. Not all shuffles of blues, and not all blues are shuffles.