How does the author describe the way a blues singer composes?

What will be an ideal response?

• "A blues singer rarely ‘composes' self-consciously. Instead, lines and stanzas seem to ‘just come,' sometimes in a rush but more often one at a time and widely spaced. Songs that blues singers memorize usually stick to one idea or event. . . . Today, a few blues songs are improvised in performance, but most are memorized beforehand. . . . In short, most blues singers today think a blues song should have a fixed, not variable, text." (Worlds of Music p. 208).