Watch the Sen-Sa-Shun: Ex. 1b online guitar lesson by Andy Aledort from Kings of Blues & Rock Vol. 8: Freddie King
This solo excerpt begins with repeated trills from the open G string to A, sounded at the second fret. Each trill is picked in a rhythm of quarter-note triplets, which means that the first and second pair of beats in each bar are divided into three even subdivisions, also known as "threes on twos." Though all of these phrases are relatively simple, there is a sense of melodic development that carries through the entire 12-bar section. Notice also the sharpness in the picking attack, another earmark of Freddie's sound.