Jelly Roll and Phrase Articulation

Jelly Roll Morton, whose birthday was recently celebrated, said, 

"Without breaks and without clean breaks, without beautiful ideas in breaks, you don’t need to even think about doin’ anything else. If you can’t have a decent break, you haven’t got a jazz band, or you can’t even play jazz."

One of the interesting, albeit obvious, changes to occur in the history of jazz has been the evolution of the approach to phrase articulation: namely, from the clear articulation of discrete phrases typical of popular dance music to an esoteric ambiguity and intricately homogeneous opacity of phrase, even down to the level of measure and beat.