Possible Clues:

• "Comus" composer Thomas
• Danish architect Jacobsen
• Composer of 'Rule Britannia'
• Barack's Education Secretary
• Composer and arranger being oddly selective
• Ex-governor Carlson
• 'Blow, Blow, Thou Winter Wind' composer
• Barack Obama's Secretary of Education ___ Duncan
• ''Rule, Britannia'' composer Thomas
• Thomas —, composer of Rule, Britannia!