Final answer:
The author develops the central idea of the passage by explaining the importance of blue notes in blues music.
Step-by-step explanation:
The author develops the central idea of the passage by explaining the importance of blue notes in blues music. Blue notes are unique chords and notes that are characteristic of blues music. The passage mentions how black musicians created a new style of music that reflected the highs and lows of life in black enclaves like New Orleans and how jazz featured improvised solos bound together by a bold rhythm and harmony. The mention of W. C. Handy as the 'Father of the Blues' also highlights the significance of blue notes in blues music.