The basic twelve-bar lyric framework of a blues composition is reflected by a standard harmonic progression of
twelve bars in a 4/4 time signature. The blues chords associated to a twelve-bar blues are typically a set of three
different chords played over a twelve-bar scheme. The lyrics
generally end on the last beat of the tenth bar or the first beat of the eleventh bar, and the final two bars are given to
the instrumentalist as a break; the harmony of this two-bar break, the turnaround, can be extremely complex,
sometimes consisting of single notes that defy analysis in terms of chords.