Related Clues:

• It has 20+ keys
• It's instrumental
• Wind on stage
• Wind in the pit?
• Musical work with a number
• Catalogued work
• Orchestral wind instrument
• Tuning-note instrument
• Magnum ___
• Numbered work of a composer
• Wood wind instrument
• Clarinet duet partner, perhaps
• Masterpiece
• Magnum piece
• __ number