Possible Clues:

• Composer of the 'Brandenburg Concertos,' in brief
• Composer of 'The Well-Tempered Clavier'
• Focus of an annual Leipzig festival
• Baroque byline
• 'Goldberg Variations' composer, in brief
• Mass producer, for short
• 'Original father of harmony,' per Beethoven, briefly
• Musical great whose grave went unmarked for nearly 150 years
• Major Baroque composer's signature
• 'St. Matthew Passion' composer, for short