Sentence:  Around the turn of the century, however, "<WSD>routiner</WSD>" or "head" music and "ear" musicians began to appear at parades. This was music more exclusively rooted in black traditions, played by men who often could not read music but who instead improvised. 
Meaning of the word marked with <WSD> tags:  A jazz musician who plays by ear (i.e. not using sheet music, but rather following along with the band and memorizing music when needed).