Possible Clues:

• Handel's 'Messiah,' e.g
• For either partner setting up duty roster at Number 10 and providing work for the musicians
• Nothing to do with rising pitch from old group of musicians starting to go off Handel's Messiah, for example
• Speaks volumes for one old type used by orchestra and choir
• "Messiah," e.g
• Love to catch informer around Brazilian city with song for orchestra and choir
• Handel's "Messiah," e.g.
• Haydn's 'The Creation,' for one
• With song or a hill with ten more
• Cantata